It may be a matter of testing different types of brushes/combs, but nonetheless, baby steps. If she takes it for 10 seconds, maybe after a while she will take it for 15 or more. It is just something else she is unfamiliar with and may take some time for her to get used to.I have invested in a brush but she likes it for like 10 secs then moves away. There is not much hair on the brush tbf.
You will also have to think about nail trimming down the line too... Keep an eye out on them to see how much they may be growing. If you are unsure about doing something like that, perhaps the vet can do it and show you how. It is something to get her used to, as some cats that don't get it done regularly can be holy terrors. So far, from what you have said about her, I wouldn't expect that - but you just never know!!