Washing a 17 month’s hair is impossible (and a rant)

Please advise?

My baby has always disliked it when water has been poured over her little head. When she was born, MIL (grandma)first bathed her and whenever she was in the country, felt it was her right to bathe my baby so I always supervised. She wasn’t bad tbh but she wasn’t the best. She doesn’t make or believe bath tome is a fun thing. Went to visit the grandparents abroad for 6 weeks recently and baby would cry profusely when grandma was around (despite being so happy on video calls with her), so I was able to wash her myself there. Whenever I do/did, I make it fun with lots of bubbles using Oilatun, some toys, I let her stay for as long as she wants. However, new environment, grandma popping her head around so frequently, meant baby would cry a lot then too (though at home, this routine is a breeze, with baby always taking me upstairs and sitting in her empty bath tub, signalling she wants to bathe [such a cute sight]). MIL thought she inform everyone that the baby cries because she’s spending too long in the bath and should be quick. This MIL is very sweet but she definitely reeks of jealousy. Her tone never indicates it, but her remarks tell it.

Anyways, the point is, when MIL used to bathe baby when she was smaller, my baby didn’t particularly enjoy it, so it’s taken a lot of hard work for me to “undo” that memory and make my baby confident and happy in the bath. However, the one thing I can’t make pleasant is when water touches her head. Even when she plays with her bath jug and accidentally gets water in her hair, she panics and tries standing up and getting out, which is so dangerous because everything is slippery. And I bathe with her, because a) I get the chance to bathe b) bathing baby is a wet ordeal with bending low on the floor to reach her bath tub, her splashing around etc I’d always end up drenched, it just made sense to bathe with her; so there are two slippery elements 1) slippery mummy and baby 2) slippery floor.

HOW