Having 2 little girls who both have ballet lessons I know how expensive the leotards can be! In ages 6yrs - 12yrs at time of posting, was £10 - £12 & now £3.20 - £4 depending on size with Free C+C too.
They also have long sleeve ones in Navy or Blue that were £9 - £10 & are now £3.20 in ages 2ys - 9yrs & a few other bits reduced too, will pop links in comments.
This ballet leotard will have her dancing around the room in comfort
95% cotton, 5% elastane
Machine washable even at 30º, tumble dry