This is what I found on www.touregypt.com/isis
. No mention of twins, though.
Isis, though worshipped all over Egypt, was specially venerated in certain cities, and the following are among the most common of her titles: --"The great lady, the God-mother, lady of Re-a-nefer; Isis-Nebuut, lady of Sekhet; lady of Besitet; Isis in Per Pakht, the queen of Mesen; Isis of Ta-at-nehepet; Isis, dweller in Netru; Isis, lady of Hebet; Isis in P-she-Hert; Isis, lady of Khebt; Usert-Isis, giver of life, lady of Abaton, lady of Philae, lady of the countries of the south," etc. From a list of title of the goddess collected by Dr. Brugsch, it is clear that Isis was called Usert, in Thebes, Aat, in Heliopolis, Menkhet, in Memphis, God-Mother, in Coptos, Hert, in Letopolis; and "Hent," i.e., "Queen," in every nome; and another important list tells us that Isis was called Ament, in Thebes, Menhet, in Heliopolis, renpet, In Memphis, Sept, in Abydos, Hetet, in Behutet, Hurt, in Nekhen, Thenenet, in Hermonthis, Ant, in Dendera, Sesheta, in Hermopolis, Heqet, in Hibiu, Uatchit, in Hipponus, Mersekhen, in Herakleopolis, Renpet, in Crocodilopolis, Neb-tept, in Arsinoe, That, or Tchetut, in Aphroditopolis, and Shetat, in Bubastis. Among her general titles may be mentioned those of "the divine one, the only one, the greatest of the gods and goddesses, the queen of all gods, the female Ra, the female Horus, the eye of Ra, the crown of Ra-Heru, Sept, opener of the year, lady of the New Year, maker of the sunrise, lady of heaven, the light-giver of heaven, lady of the North Wind, queen of the earth, most mighty one, queen of the South and North, lady of the solid earth, lady of warmth and fire, benefactress of the Tuat, she who is greatly feared in the Tuat, the God-mother, the God-mother of Heru-ka-nekht, the mother of the Horus of gold, the lady of life, lady of green crops, the green goddess (Uatchet), lady of bread, lady of beer, lady of abundance, lady of joy and gladness, lady of love, the maker of kings, lady of the Great House, lady of the House of fire, the beautiful goddess, the lady of words of power, lady of the shuttle, daughter of Seb, daughter of Neb-er-tcher, the child of Nut, wife of Ra, wife of the lord of the abyss, wife of the lord of the Inundation, the creatrix of the Nile flood."
From a number of passages in the texts of various periods we learn that Isis possessed great skill in the working of magic, and several examples of the manner in which she employed it are well known. Thus when she wished to make Ra reveal to her his greatest and most secret name, she made a venomous reptile out of dust mixed with the spittle of the god, and by uttering over it certain words of power she made it to bite Ra as he passed. When she had succeeded in obtaining from the god his most hidden name, which he only revealed because he was on the point of death, she uttered words which had the effect of driving the poison out of his limbs, and Ra recovered. Now Isis not only used the words of power, but she also had knowledge of the way in which to pronounce them so that the beings or things to which they were addressed would be compelled to listen to them and, having listened, would be obliged to fulfill her bequests. The Egyptians believed that if the best effect was to be produced by words of power they must be uttered in a certain tone of voice, and at a certain rate, and at a certain time of the day or night, with appropriate gestures or ceremonies. In the Hymn to Osiris it is said that Isis was well skilled in the use of words of power, and it was by means of these that she restored her husband to life, and obtained from him an heir. It is not known what the words were which she uttered on this occasion, but she appears to have obtained them from Thoth, the "lord of divine words," and it was to him that she appealed for help to restore Horus to life after he had been stung to death by a scorpion.
In the Theban Recension of the Book of the Dead is found a Chapter (No. clvi.) which was composed for the purpose of bestowing upon the deceased some of the magical power of the goddess. The Chapter was intended to be recited over an amulet called thet, made of carnelian, which had to be steeped in water of ankhami flowers, and set in a sycamore plinth, and if this were laid on the neck of a dead person it would place him under the protection of the words of power of Isis, and he would be able to go wheresoever he pleased in the Underworld. The words of the Chapter were: -- "Let the blood of isis, and the magical powers (or spirits) of Isis, and the words of power of Isis, be mighty to protect and keep safely this great god (i.e., the deceased), and to guard him from him that would do unto him anything which he abominateth."
The symbol of Isis in the heavens was the star Sept (Sirius), which was greatly beloved because its appearance marked not only the beginning of a new year, but also announced the advance of the Inundation of the Nile, which betokened renewed wealth and prosperity of the country. As such Isis was regarded as the companion of Osiris, whose soul dwelt in the star Sah, i.e., Orion, and she was held to have brought about the destruction of the fiend Apep, and of his hosts of darkness by means of the might of her words of power. As the light-giver at this season of the year she was called Khut, as the mighty earth-goddess her name was Usert, as the Great Goddess of the Underworld she was Thenenet, as the power which shot forth the Nile flood she was Sati, and sept, as the embracer of the land and producer of fertility by her waters she was Anqet, as the producer and giver of life she was Ankhet, as the goddess of cultivated lands and fields she was Sekhet, as the goddess of the harvest she was Renenet, as the goddess of food which was offered to the gods she was Tcheft, and lived int he Temple of Tchefau, and as the great lady of the Underworld, who assisted in transforming the bodies of the blessed dead into those whrein they were to live in the realm of Osiris, her name was Ament, i.e., the "hidden" goddess. In this last capacity she shared with Osiris the attribute of "giver of life," and she provided food for the dead as well as for the living; as Ament also she was declared to be the mother of Ra. In fact, at a comparatively early period in Egyptian history Isis had absorbed the attributes of all the great primitive goddesses, and of all the local goddesses such as Nekhebet, Uatchet, Net, Bast, Hathor, etc., and she was even identified as the female counterpart of the primeval abyss of water from which sprang all life. From what has been said above it is manifestly impossible to limit the attributes of Isis, for we have seen that she possesses the powers of a water goddess, an earth goddess, a corn goddess, a star goddess, a queen of the Underworld, and a woman, and that she united in herself one or more of the attributes of all the goddesses of Egypt known to us.