Thank you all for such balanced replies!
Sorry for not responding, in the whirlwind of everything I totally forgot that I'd started this thread!
To clarify a few things, we're in Scotland so things are a little bit different up here. My daughter is about to go into S3 this year.
Our local school is really not great, way down the bottom of the league table and so are the other nearby schools.
My daughter isn't struggling academically, but she's really struggling mentally. She loves learning and really needs to be stimulated but she feels like she's stagnating and she's bored and her behaviour is deteriorating as a result. She's awaiting an ASD assessment but it could be another couple of years for that. The behaviour in the school is awful and I think she might also be anxious about what's going to happen next each day. She's losing her love of learning and as a result she's depressed to the point of feeling suicidal and we've had to involve CAMHS.
We've had 2 family members offer to help us out, to a small extent, so I'm feeling a bit better because I know that the first 2 years fees are covered , the last 2 years should be ok, but we could release funds from our mortgage if necessary.
The school advised me yesterday that when our younger child joins the school they'd be eligible for a 100% bursary if they pass the entrance exams so that's a massive relief!
We will definitely have to stop any foreign holidays and just stick with camping etc and no new furniture or cars but I'm thinking we can probably do it.
Feeling very nervous about it all though!