It is probably either a low-end Custom Sport or a mid-grade Kokusai (International), but I cannot tell for sure from the picture provided. An International is arguably worth the ante, but the price seems a little steep for a Custom Sport, which is a boat anchor. If it is an International, it will have aluminum cranks and a CrMo sticker on the frame.
The frame size should be OK for her, unless she is really long in the legs. My wife stands 5'6" and happily rides a 21" = 53.5cm frame.
__________________
"Far and away the best prize that life offers is the chance to work hard at work worth doing." --Theodore Roosevelt
Capo: 1959 Modell Campagnolo, S/N 40324; 1960 Sieger (2), S/N 42624, 42597
Carlton: 1962 Franco Suisse, S/N K7911
Peugeot: 1970 UO-8, S/N 0010468
Bianchi: 1982 Campione d'Italia, S/N 1.M9914
Schwinn: 1988 Project KOM-10, S/N F804069