Yes she looks in foal but she also looks like she has a grass belly (fat but only in the tummy region). Our one racing mare, no matter how in shape she was, always had a grass belly. Also my arab was "fat" but many people asked when she was due!
I know money is tight, and personally we never have a vet out unless we believe the mare is in need. We judge whether they are infoal if they come into heat or not.
Has she come into heat? A good way to check is to bring a stallion/colt (if available) or a studdish gelding and see her reaction. If neither are available rub near her tail area. If she has a, for lack of better terms, peeing i guess, than shes in heat. Keep an eye on her OR call a vet if you really want to know.
A Dog looks up to a man,
A cat looks down on a man,
But a patient horse looks a man in the eye and sees him as an equal