We use Barking Heads tender loving care (chicken &r rice) with Tia and it suits her fine. I chose that one because she was on Barking Heads puppy days before which was chicken salmon and rice, I didn't want to change ingredients too much and risk upsetting her nice firm stools
Prior to Barking Heads Puppy days she was on James Well Beloved puppy and then junior but found her stools were loose all the time.
I would recommend the Barking Heads definitely to try, especially as you think it's the closest ingredients wise to what Sally was on before. The ingredients seem pretty straight forward.
You get get the smaller 2 kg bags from some places (useful to trial) but I'm sure they will send you a sample if you request via their website anyhow.
Hope it all works out for you and Sally.