Hi Tina,
Congratulations on your lo!
My babies were 12 weeks prem and came home after 9 weeks. They are now 8 months old, so roughly 5 months corrected. They are still on a 3 hourly routine.
Is she still on a 3 hour routine? At the moment, I would treat her as a 4 week old and keep activity time to a minimum. EG, feed, nappy change, then bed. She will start extending her A time as she gets older.
My 2 still can't manage more than 1 1/2 hours A time.
If you need any other help, feel free to ask.