Answer
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
1- If removing hair is for medical reasons, it is allowed for a woman to be waxed by another woman.
2- If it was for beautification only, a woman should do it herself and should not allow another female to do it for her.
Answering your question, Sheikh Kifah Mustapha, the Imam and Director of The Prayer Center of Orland Park and representative for Dar El Fatwa of Lebanon in the US, states:
In the general term of the waxing act itself yes, a woman can get waxed by another woman. But there are different views about what part of another woman’s body is allowed to be exposed to another woman and here as to your question, to be waxed by another female.
I lean to the view that the awrah of a female to a female is that which is between knees and belly.
With that being said, for medical reasons only, even that area is allowed to be exposed for the purpose to preserve the well-being of the person.
So if removing hair in that area is for medical reasons, it is allowed, but if it was for beautification only, the female should do it herself and not allow another female to do it for her.
Almighty Allah knows best.