lavender is linked to having some influenced to infertility, so maybe her tea might’ve had something to do with it...?
if the author is going to depict corsets accurately (which she hasn't done so far, lol) the corsets wouldn't be an issue since everyone wore corsets in the time era this is based off of, even men occasionally and maids always. unless it was a new corset that she was breaking in, there shouldn't be any issues, but the author isn't from the west so information about corsets aren't as readily available, which sucks because corset bad argument was literally something the patriarchy created to mock women and their businesses (corset-making was a women-owned business)
Maybe she can't have children because her corset is too tight so it injured her belly or perhaps drinking too much tea increases infertility? Maybe both or none ?? It's just a hypothesis ╮(￣▽￣)╭