All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
If this girl has reached the age of puberty, it becomes obligatory on her to wake up for the Fajr prayer. The age of puberty for a girl is by having menses, wet dreams, starting to have thick pubic hair, or by reaching the age of 15 lunar years old according to the view of the majority of the scholars . Therefore, if she did not reach the age of puberty, she is not obliged to wake up. However, she should endeavour to wake up so that it would become easier for her to wake up when she becomes pubescent. For more benefit, please refer to Fatwa 119331.
As regards her parents, the majority of the jurists are of the view that they are obliged to wake her up, this is because they are of the view that ordering the child to perform the prayer that is mentioned in the narration of the Prophet, the Prophet "Order your children to perform the prayer when they are seven years of age." [Ahmad and Abu Daawood], implies obligation. The same ruling applies to what is needed for performing the prayer, like purity, performing the prayer at its prescribed fixed time, fulfilling its pillars and conditions and so forth. So, it is an obligation on the guardian of the child to order him/her to do all these things and teach him/her the prayer.
Furthermore, the parents should be keen on encouraging the children to learn the correct creed, to realize that Allaah is watching them all the time, to have a good moral conduct according to methodology mentioned in the Quran about Luqmaan (the Wise) in guiding his son.
Moreover, they should urge them to do the religious obligations which they are able to do, like fasting and the like, in the same way the companions used to do this with their children. Similarly, a girl should be accustomed to wear the Hijab.
Allaah Knows best.