1year old Tabby troubling our 7 year old daughter

[ImNotAFlower]

We have a 1 year old tabby, who in the last couple of weeks has out of nowhere snapped at my 7 year old DD and also swiped at her (claws out) as she has gone up the stairs.
Nothing untoward has gone on between them in fact he is 'her' cat. She feeds him and makes a fuss of him when he wants it.
Bizarrely he still goes off to bed with her every night.
We have a 3 year old DS who also doesn't trouble him either but he isn't getting the same treatment.
Does anyone have any ideas what might be going on?

Trying to get her to play? Roll a ball or toy in the opposite direction to direct the play.
Is he neutered?

Sounds like he is bored, swiping at people walking up the stairs is a favourite past time of bored cats. Get her to throw a ball, scrunched up bit of paper at him as she walks past on the stairs.

Hi, thank you for the replies.
He is neutered, it is only her though, anyone else can go up and down no problem.
When he snapped at her he was just sat on the sofa.

One of mine bites when over stimulated. Can be stroking her and she gets loved up to the max and bites. Not really hard. But she can't control it.
Both of mine bit as kittens.

That may have been it. He was tapping her on the head to stroke him five minutes before so like a good cat slave she did! Maybe he got over excited. Thank you.

Mine doesn't break the skin. It just all gets very exciting!