Where did it all go wrong?

[Fragnes]

My two-year old dd has gone down really well and slept through for as along as I can remember (I was never complacent about it but was very happy!) until the last couple of weeks. It started a couple of weeks ago: she'd had an overly long nap, I put her down in the evening as normal and went to sit in the garden, I realised about 30 minutes later she was hot and bothered and crying (my fault for not listening out but she was 100% at going straight down so I didn't think to).
Anyhoo she seems to have developed a bedroom anxiety, I have cut the naps out so now she goes down OK - I have to now sit at her door till she drops off. But she always wakes in the night now and ends up in our bed. How can I get her to sleep through again?