Not insanely expensive either. Depends on the riding she wants to do longer term, but it would be an improvement over gas pipe and not as £££ as custom painted Soma.
I can't speak for the component quality. Just throwing out ideas for consideration given the request.
My other half is 5'4" and we have gone through this a few times. Surly do a few 650b wheeled smaller frames (Straggler and maybe one more) as do one or two other bike makers.
Odd option but look at Tokyo Bike Bisou. All 26" wheels, mixtes and built for shorter riders.
https://www.tokyobike.co.uk/tokyobike-bisou.html
Not insanely expensive either. Depends on the riding she wants to do longer term, but it would be an improvement over gas pipe and not as £££ as custom painted Soma.