HI, that's fantastic news that your daughter is enjoying the sport. A friend of ours is just back from the South African open where his 13 year old daughter took gold in a stage beating everybody, we are all super proud of her.
I don't want to piss on your chips, but don't want you wasting money either. A .223 can be competitive but it needs a very fast twist barrel, the correct throat and carefully loaded ammo. In addition you mention a "target" rifle, if this is a TR style rifle (shot from a sling) then it may not be suitable to take either the scope or the bipod, I would just check on these first.
Other than that I wish her all the best and look forward to seeing her on the point.
p.s do you make it to Bisley to shoot, if so let us know and we can try and organise for some other youngsters to be about in order to make her feel as welcome as possible.
Ewen