I'd focus on suspension and wheels first, I can tell you first hand that coils make a huge difference to the handling. Your car looks pretty clean so just doing suspension and wheels will make it look amazing. You can change out the suspension yourself or get someone to do it for you. You could spend the whole 2k on coils if you wanted!! They range from about 400 up!
Maybe drive it for awhile and then move on to engine upgrades - I guarantee a bunch of expensive stuff will break on her in the near future. It's the mk3 way. Ask lots of questions - everyone on here has been in your shoes and will have lots of suggestions.
Also - I think Seb (bugracer) on here built up a vr6 Auto for a girl in Sydney and got pretty solid performance out of it, although there was a fair bit of debate as to whether it was worth it with an auto! But the customer wanted it as a daily I think.