Yes, please post some photos of the possible parents! Could you contact the registry and have new papers sent to you? If she is pregnant, then you've already saved a bundle on stud fees. Not much more $$$ to shell out until it's born. Good luck, hopeit works out the way you want!
You're going to want to start feeding a fortified grain, preferably one specially formulated for pregnant mares. And when it comes to this you don't get to be irresponsible and go "oh, I'll give her two scoops," you need to weigh her, weigh the feed, and feed according to the labels. In addition, you need to be weighing the hay. Weigh her, weigh each and every flake of hay, and keep it plentiful and constant.
She needs to have regular vet visits, and she needs to get the proper vaccines in the proper stages of pregnancy, and helped along whenever needed. She may need monthly farrier care, especially in the later stages of pregnancy.
You're going to want to invest in a supplement for her, to help her along – probably more than one. There you really have to do your homework in researching – going beyond the labels to look at ingredients and what best suits your mare.
Moreover, her deworming schedule not only needs to be consistent, but you need to select dewormers that are approved for pregnant mares – which usually cost more than an average dewormer.
After the foal is born, you're looking at more vaccination and deworming costs specially suited for the baby. You will spend every day with the foal, probably pay for a trainer's input and help, and continue to provide special care for both mare and foal. You will be looking into supplements for the baby, a nutritionally balanced diet, and lots and lots of money put in to equipment and care.
This is not something you do because you want a "cute foal." There are plenty – many thousands –*of "cute foals" that desperately need a home and care. This is a huge investment, that produces no income.
I have given you a very rough outline of the basis of care that you need to provide. This costs many thousands of dollars, and it's not something you do on a whim, or by accident. Think about what you're about to take on, and, if you're at all honest with yourself, you'll probably decide against it.