My preference would be something smaller than a 1m as they are much more of a handful on dry land.
This was an issue for me, with my 1m.
But less than 600mm IMHO tend not to sail to well. There are a few exceptions, but they are few.
Generally speaking, bigger sails better, but this must be balanced with practicalities. You daughter needs to be able to handle it easily, and you need to be about to transport it easily.
Also think of storage at home. If you want to display in room, the Vic is manageable (see Boomer's pic). A 1m will sit on a coffee table and almost touch the ceiling. Or you need to keep it on the floor.
When thinking of size of a model, think of volume/cube/cube root for a moment. A 500mm boat may be half the length, but it is only a quarter of the size of a 1m boat.
The TT Odyssey (610mm) looks very small next to the TT Victoria (780mm).
The TT Victoria looks small next to a 1m.
TT Vic (Boomers pic will give an idea of size)
Length: 30.7" (779mm) Mast height: 42.8" (1086mm) Width: 7.7" (197mm) Weight: 4.6lbs (2100g)
TT Odyseey
Length: 24.01" (610mm) Beam: 7.87" (200mm) Mast Height: 31.10" (790mm) Sail Area: 268.2 sq in (17.3 sq dm)
Overall Height: 41.34" (1050mm) Overall Weight: 3.5lb (1.6kg)
Typical 1m
Length: 39" (991mm) Beam: 6.75" (172mm) Sail Area: 744 sq in (48 sq dm) Mast Height: 51.4" (1306mm) Overall Height: 67" (1580mm) Overall Weight: 7.7lbs (3.5kg)