Twitchy legs

I do suffer from time to time (although not as badly as some) and find if I take a Nurofen when it starts it does seems to help. I don't get it every night just occasionally so this may not be a solution for someone who suffers every night.

Here's one link:
www.gransnet.com/forums/health/a1219999-RLS-3rd-really-bad-night-of-no-little-sleep-Im-pacing-in-the-garage-in-the-wee-hours

There are a few threads about this - search for "restless legs". I'm another sufferer.
If I remember right there are different reasons for it. I think mine comes from a bit of hip arthritis and (fingers crossed, b'e'r) a hot water bottle under the hip helps a bit.
Some people take a medication used for Parkinsons.
Your daughter should ask her doctor.