i'm really tempted to say a cornford carrera, but i'm not sure if the cleans will be good enough. they're decent, but not amazing. the harlequin is allegedly (i haven't tried it) pretty similar, except it misses out on some of the bells and whistles- switchable power valves, fx loop, etc- and is quite a bit cheaper.
the cornell romany plus is excellent, but might not get heavy enough. they also do a plexi which is low wattage too, and which is also meant to be great, but i haven't tried it.
there's always martamp/mjw as well, but i haven't tried those. hear great things on the forum about them, though, and the prices are excellent.
blackstar artisan 15 might be worth a try? i didn't really like it, but it might suit the stuff she's playing. if she plays much 80s rock, though (and assuming you mean the same thing as i do by 80s rock :lol: ), i'd have said the cornford would be better.
Big problem as usual is the weight... most of those are 1x12 combos, which aren't ridiculously heavy, but will still probably come to around the 20kg mark... though the martamp would be available as a head (as is the blackstar), just that means you need a separate cab...
just to check, you're/she's willing to go all-valve?