My teen sims won't do her homework

Hi everyone,

I'm having a really annoying problem in my game since last night. When my Sim "Anne-Marie" aged up into a teenager she got her new homework straight away. Of course I made her do it instantly, but then when she went to school and came back with new homework - anytime I command her to do it, she pulls it out does it for only a few seconds and cancels the action completely. I've reset her through the toolbar and by clicking on her, and it still hasn't fixed this.

However, my kid Sims are still able to do their homework.

I'm really confused by this and getting frustrated. Does anyone have solutions at all? It'd be a great help!

- Thanks in advance.