Improve outdoor audio recording quality and clarity

I (26F) live with my 16-year-old brother. It is me and him and my girlfriend stops round regularly. He recently had a new girlfriend (also 16) stay over at our house. While I was at work and my brother was sleep I saw that she had gone into my shed on my outdoor security camera, thinking that was strange considering it was a warm, sunny day, yet she went into the shed at the back of the garden, which is quite far from the house I reviewed the footage (with audio), and saw her come out of the shed while on the phone and walk down the garden path and started pointing out every single one of our security cameras. As she was the far end of the garden the audio does have some clipping due to the wind/birds tweeting, however, I did hear her say: "Camera there, two cameras over there, one down there near the window" then she turned around and pointed at our back gate and said "That's the back gate that (inaudiable mumble) jump over" After that she goes back into the shed to continue her conversation so I can't hear anything other than a few audible clips now and then, such as her saying my full address and the street name which leads to the back of my house and 'they also have two cameras on the front' then something inaudible for a few seconds and then what sounds like 'you can't get past there'. I showed some co-workers the footage and they believed she said the same thing I thought I could hear, but it is worth noting that section is not 100% clear other than my full address and her stating they is 2 cameras on the front. I have only met her a few times, maybe 3-4 times at most. So when I got home me and my girlfriend asked my brother to come talk to me real quick before he goes out, she followed him to the door but i gestured for just him to come and then I quietly spoke, but it is worth noting she could probably hear as she was just stood in the doorway of the garden, and said if he knew why she was pointing out and recording our security cameras, he said she actually woke him up and “Your sister’s going to think I’m weird on the cameras.”. It is worth noting she was not aware the camera has audio. I asked him what she meant and apparently she was talking to her sister about a client of hers (her sisters client) who lives on my street/near my street so they was just wondering where he (my brother) lives. I said no, they is audio and she is pointing out our cameras specifically, my girlfriend then jumps in loudly and says 'No, that is not what she was doing, I suggest you speak to her' or something along them lines, the whole conversation lasted a minute, I do understand the way my girlfriend spoke could come across like she was accusing her or something. Anyway, after that my brother comes home like 10-15 minutes later and she has broken up with him, blocked him and said I should've asked her directly. Apparently she was saying some things about me or that is what I gathered as my brother said he shouted at her to shut up or something because she was getting loud and he said he was worried I would hear and at the end of the day I am his sister and I do a lot for him and I wouldn't of asked if I didn't have a reason, I didn't pry what she was saying as I am more bothered about my brother being upset than a teenager potentially calling me names lol. but now I feel bad, like I caused something and it has resulted in my brother being the one upset? Like did I overstep? Is it normal to be questioning what I saw? Should I have gone about it a different way? I didn’t mean to cause drama, but it looked suspicious, and I honestly would've asked the same thing if anyone even my brother was doing it. So... **AITAH for the way i approached this?**