Bullmastiffs

Hello, I am hoping other Bullmastiff owners can help me out here. When we first got Sadie at 3 mo. she was not trained in ANY kind of way so potty training her was a difficult task. Once it started becoming warmer we put her out in her pen outside during the day while we are at work and in the evening she sleeps in a crate. I am not sure if she can hold it all day to be inside because she never did it before it got warm. Now, she rarely went potty at night in her crate from day 1 and we probably haven't had any messes at night for 2 months. Last night there was a horrible storm and this morning when I woke up she had pooped twice and peed. The storm even woke me up and scared me a little. Do you think this was due to the storm waking her up and scaring her or a potty training issue? Please help me! I want her to be trained so she doesn't have to be locked up at night or even during the day but right now we just can't trust that she's ready. Thank you!!