Well you've done all the right things so far! Sorry you've got such a shock, absolute nightmare
Just keep her food and water topped up, she would benefit from protein rich foods like plain chicken or eggs (hard boiled or scrambled plain no seasoning) for her milk production but otherwise yeah, just leave her to it.
Strongbrew Hamstery has a great crash course here
https://strongbrew.ca/crashcoursepregnancy that would be more help than I could be. Or the pet shop for that matter.
Good luck and god speed new hammy grandparent! I hope it all goes smoothly and you keep us all pupdated!
