my toy poodle is only 4 pounds and she can hold it 12 hours easily and has never had a problem, she only goes out 4 times day. My little guy who is 10.5 weeks can hold itfor 5/6 hours at night. He goes out a 9 then not again until 1 or 2 a.m per his request, he whines I take him out and he goes, I take him out every 1.5 to 2 hours though during the day.
I guess I just have a hard time believing that because of thier size they arent suppose to be able to hold it more than 8 hours? My bigger dogs have a harder time holding it more than my little guys do.
I hope she stays healthy for you.