Ps do take into account the weather, travel stress, competition stress if and when her weight drops. The latter two are big factors, especially if there is a sudden change in her routine.
Oh yes this is a good point. I'm away on holidays in a fortnight and she's off to stay with friends.
She did stress a little last time i went away so will be interesting to see if she drops weight at all this time.
Luckily he is a retired friend so will throughly spoil her with attention all week!