Originally Posted by kevinshorses
The papers belong to the person that paid for them. They don't belong to the horse. There are many reasons that a seller may retain the papers but they have every right to do so.
Broodmares are generally bred until they no longer settle or they are unhealthy in some way or they die. What should a person do with a broodmare take her out and shoot her when she turns 20 just because she's twenty?
I agree with you KevinsHorses that broodmares don't need to be retired simply because they are over the age of 20, however the OP was asking this question in relation to the age of her horses Mother.
I.e. Is it possible for the Dam to have been 19 when the OP's horse was born, therefore making her
horse 20 (as indicated by the seller).
To the OP: The answer is that yes, it is possible for mares to raise healthy foals at the age of 19, however given your concern regarding the sellers honesty (or lack thereof) I think you should be skeptical of anything she tells you.