It’s not a terrible case of mansplaining, but to break down why she may have felt that way: “I hear that’s recommended for safety” - I’m sure if she’s into this activity she’s aware of safety concerns and “BSC has a better space for Olympic lifts than BKB” - I assume these are gyms you both have been to and you may know this based on her profile? I think she’d be aware of the space available at each.

I obviously don’t know what was in her profile to prompt the conversation, but this kinda reminds me of when I used to have “a life goal of mine is to run a marathon” and I would get responses like “have you ever done a 5k?” Sometimes it’s best to ask questions that assume the woman knows what she’s talking about.

I don’t think her reaction was necessarily called for, but this could be happening every time a match asks about her training and at some point it gets old.