I'm going to venture a guess and say that she is bred and you absolutely need to contact your vet about coming out to look her over. No just for a definite answer, but because there are important shots that need to be given 30 days prior to foaling. They should be given before a mares starts to bag up, but I'd say that if she's bred, she's already bagging. Which is why it's important to get your vet out to take a look at her asap.
She still looks fairly thin. Dietary needs for a pregnant mare so far along as also different then regular feeding. Your vet can recommend what this particular mare will need to sustain herself, and a foal if she is indeed pregnant.
"The greatest pleasure of a dog is that you may make a fool of yourself with
him and not only will he not scold you, but he will make a fool of himself too."