Thanks all for the replies!

T is planning on returning after about 6 months of leave but I have difficulty believing her as I have two T's in the past who both said similar things but never returned after their maternity leave. I am also unsure if I will see another T during the time current T is on leave. I worry about becoming too attached to a new T and being conflicted about if I should stay or go back to old T when and if she returns.

Anyway, I definitely want to give her a thank you card/letter and I thought about buying coffee for us both to have together but T has been drinking less coffee since becoming pregnant so I don't know about that, I will obviously ask her first.

I've literally had three T's leave me (two on maternity leave) and this will be the fourth so yeah... starting to think I'm cursed. The longest I have seen the same T is 2 years and current T I've seen for about 1.5 years now but it might be a bit longer... I honestly don't remember but long enough for this to feel like a big deal.