Some of these things I think are fine if they're isolated and done within a normal family relationship, but not in the context of wider abuse.
1. Hid your comfort blanket because she thought it was a game, many times. Got her son (daughters bio brother) to taunt.
Unacceptable as it seems repeated.
2. Chased daughter around the house with a whole dead fish, holding it by the tail, with the face looking at her. It was going to be cooked for tea, bought at the supermarket.
Could be funny as a one off isolated incident.
3. In a mother/daughter evening about puberty, was the only adult who raised her hand during 'Question time' and said that as her daughter was so wide what tampon would be suggested.
This is completely humiliating and unacceptably abusive. Also logically how the f would she know this info?!?! And what teenager is "wide"?
4. Helped out at the Youth Group her daughter attended but not the one her son did.
I think this is fine. More appropriate for her to help out at the same gender youth group as her.
5. Said publicly in front of daughter regarding a Lucky Dip that her son should choose the ticket because he's 'the lucky one'.
Fine as a joke / isolated incident.
6. Daughter had to buy first bra from a Girl Guide jumble sale because Mum laughed when she asked if they could buy her first one together.
Unacceptable. Didn't provide items that young women require as an essential.
7. No purchase of sanitary products, daughter had to buy them out of earned pocket/bday/Xmas money. Daughter was at fee-paying school funded by other relatives.
Unacceptable in not providing essentials. I have zero clue why a mother would do this to a child.