Hi Karenj! We got our beautiful BM from Burningwiid Bullmasitff. The lady's name is Barbara and is a very experienced breeder and is located in NY state. We are from NJ also and my wife did alot of searching to find the right breeder for us and we are very happy. Their website is
Burningwood Bullmastiffs
^^^+1! We picked our pup up from Barbara in June and couldn't be happier. She pretty much has an open door policy-especially if your are lucky enough to be selected for one of her pups. Whenever my wife or I had a question she had no problem answering or letting us stop by to see them. She is also on the NY/NJ border so she may be your closest bet.
I'm not sure if she is going to have another litter this year, but if your sister isn't looking to wait that long she can try Fern at
http://www.bullyboybullmastiffs.com/ We just missed out on her last litter but I think she may have one planned for the fall or winter. She can also try the ABA directory
Breeders Directory - AMERICAN BULLMASTIFF ASSOCIATION
The Tri-state area is a great region for reputable Bullmastiff breeders. We live about 20 minutes from one of the most reputable Bullmastiff authorities in Helene Nietsch. While we didn't get a pup from her, she did mentor Barbara and she was more than happy to recommend her vet and talk shop.
Even if there are no pups available now, it doesn't hurt to call and ask. Good Luck!