YES!!!!!
Can she multi-task? That has always been a huge issue for difficult child 1, but not at all for difficult child 3 until this year, and now it looks almost certain that taking citalopram has greatly stuffed up difficult child 3's memory being laid down, which flows on to not being able to multi-task.
The way for Jumper to approach maths, is step-wise. Learn how to identify the steps, make notes as she goes, and rely on her notes and ability to do this. Intensive tuition from someone who is an expert in helping kids with multi-tasking issues will help her get confidence, which is a big part of this battle also.
And she may just need time. She might not be able to do this until she's 27.
Marg