She has reached the age of puberty but she is not strong enough to fast

A girl has reached pubertyat the age of eleven and she is weak. Does
she have to fast? If she is unable to fast then what should she do?.
Praise be to Allaah.
If the situation is as described, then she has tofast because
menstruationis one of the signs of puberty for women, if it comes when
she is nine years old or more. If she isable to fast then she mustdo
it at the proper time, and if she is unable to do it or she faces
extreme hardship in doing so, thenshe may not fast but she must make
up the days that she did not fast whenshe is able to do so. End quote.
Fataawa al-Lajnah al-Daa'imah li'l-Buhoothal-'Ilmiyyah wa'l-Ifta/