There's the reason for the funny poo's. Probiotic Yoghurt should ideally be natural, notflavoured and whats with the cottage cheese, not to mention bananna's?
How do you know her approx age as being 14 months, when she's an ex-bat? You may have had her that long but she will have been to hell and back by being forced to lay at least twice a day for at least six months.
This is why ex-bats don't have a very long life, at three they are the equivalent of being 90+ in our years simply because of what has been taken out of them.
It could be that she is simply heading towards her natural end of life as opposed to being ill.