I play guitar and Piano I can't say to what standard because I play very differently on the two I am primarily a Jazz/fusion player on Guitar, but I play more classical on Piano (I'm a passable jazz pianist but not great) and I'm technically better on the Piano but I'm more unique on the guitarAlthough I would say that whatever instrument she learns she will be able to play with other instrumentalists simply because that how music works, it doesn't have to be an orchestral one, but as advice I would say let her pick, as if she picks she is more likely to work hard and play better if it's an instrument she truly wants to learn, but my other piece of advice would be to wait until she is grade 5 on piano and playing at an intermediate standard at the minute she is still fairly early on in her piano training and starting two instruments here could be a bit much
the idea of an orchestral instrument may be good, especially if the instrument is different from the piano: in this way she would receive a more complete musical education.maybe an instrument like cello or violin is the best because tuning it you develop your "ear", but it can be too difficult to study 2 at the same time
Contrabass I like playing in orchestras so that I will also be exposed to symphonies, orchestral music etc. and not just piano music. It is also challenging to develop the ear in lower pitches
My second instrument is the flute. It used to be my first and I used to be quite good at it, but when I stopped playing in chamber groups and orchestras I sort of lost the will to practice regularly. The tiny muscles around your mouth really need regular exercise to function properly, so I swapped to piano instead. My piano playing can take a few days off better than my flute playing, and I think piano is more rewarding as a solo instrument. That said, I miss playing with others and had lots of fun playing in different chamber groups when I was young(er). A second instrument could give you more opportunities to learn how to relate to other musicians, how to follow a conductor etc. than the piano alone.
Thanks for your advice. Her preference on the guitar was pretty much influenced. For trumpet, she concerns it'd shape her lips differently with the buzzing (will it?).
The shape of the embouchure (the face muscles needed to play a wind instrument) is usually only a concern for those who play multiple wind instruments across families. If you play a wind instrument it is best to stick to playing instruments in the same family. Eg: Single reeds such as clarinet and saxophone. Double reeds such as oboe and bassoon. Brass such as trumpet, trombone, french horn, tuba, etc. Flute tends to be sided more with the woodwinds. Playing both brass and reed instruments is usually discouraged as the embouchures and techniques are markedly different.I play clarinet as a second instrument, thus I tend to stick to woodwinds and avoid brass.