I would ask the breeder if she could have her liver enzymes tested BEFORE you bring her home. Hopefully, you could detect any problems before she even gets there - that would be best for you. It would be hard to get attached and then have to return another puppy.
Although, I had Lucy's liver enzymes tested when she first came home and she still ended up having MVD - undiscovered until a couple of months later and with a more direct test. (BAT)
Best of luck to you. The very best thing would be to ask for a refund and start looking for another breeder.
That's what everyone on here advised me to do when Lucy's sister was PTS for liver shunt (before we brought her home). I didn't listen; and now I have a little girl with liver problems. Hers seem to be mild, thank goodness, but there were 2 dogs out of the same litter with liver issues.
And severe liver issues can mean very expensive testing and surgery so . . . just be aware.