It might be worth getting your daughter to look at some of John Field's piano concertos. Whilst some of these are extremely challenging (and contain ferociously difficult passages) others such as his first (written in 1799, with an early Romantic style) are simpler.
Solo versions of the 1st, 2nd, 3rd, 6th and 7th piano concertos can be found here:John Field Sheet Music
The full orchestral scores however, are more difficult to find. Other possibilities may include Schumann's A minor concerto and Prokofiev's first piano concerto.
On a side note, does your daughter have an orchestra with which to perform a concerto? If not, it might be worth her while looking for piano trios/quintets for the moment (of which there are many) and finding a few talented string playing friends to perform them with. A lot of early 19th century piano trios/quartets still treat the piano as a concertante instrument within the ensemble, so it would be similar to playing a concerto.
 Perhaps your daughter may also benefit from trying some pieces for piano with orchestra that aren't piano concertos. A lot of these exist from the 19th century (think of Chopin, although beyond your daughters level). Some other suggestions could include:
Saint Saens' Caprice Valse 'Wedding Cake' for Piano and strings
Kulau Piano concerto in C Op. 7