my english bulldog.

Question
hi. my bulldog is about 2 or 3. one night, my sister came into  the room, and started to pet him. he was quiet when this happened, but didn't move.when she stood, he got up from his spot next to me and crept toward her. then he jumped and bit her. it left a few marks, but nothing big. he was fine the rest of the night. the next day, he was fine again. she came out into the dining room, and tried to give him a treat. again, he growled, and tried to attack her. he is only doing this with her, and no one else. Please help.

Answer
Active aggression requires an in person evaluation by a credentialed animal behavior expert (Ph.D. or DVM...NOT a dog trainer.)  Your dog may be responding to a rank signal (misinterpreting your sister's actions), may be attempting to establish rank, may be responding to having been startled when sleeping and now has an acquired aggression problem toward her as a result, and any other number of problems.  None of this can be addressed in a text box.  Call the veterinary school closest to your home (even if it's in another state) and ask for a referral.  Meanwhile, have your sister totally ignore this dog.