Accidental litter

Hi,

We are considering a puppy from an accidental litter, with a limited AKC cert. Ok with the limited since we don't want to show or breed, looking for a companion animal.

The situation: the mother is too young to have done her medicals. AND is line bred with her grandfather.

Our current family situation: me, my husband, my 18 year old daughter (would be her dog), a 10 yo Labrador doodle, a 12 cat.

I would appreciate any advice you have in this situation. I don't know much about line breeding or Beaucerons in general. In the past, we've had mixed breed dogs. Is there a big risk for health or behavior issues in your opinion?

Thank you in advance for any insight!