Med-head reporting for duty.
Do you know what a forester does? That's not a sarky question, it's genuine, because I have no idea what the job-spec involves in whatever period you are setting this particular scene. If it's chopping down vast oaks alone and having to wield huge axes, then I'm going to chuck the book if the MC is a 7 stone slim girl with wrists like limp rhubarb. In the absence of power tools and technology, the reason some things were seen as a man's job is simply because most women lack the upper body strength required for the work. Consequently even if they can do the job, they might take longer or eg produce less coal per shift, therefore aren't worth the same to an employer.
Also, although peasant women worked, and worked bloody hard because they had to, they didn't work in isolation. A community organises itself to share work-loads as far as possible, so if she is doing what is seen as man's work, who is doing the woman's work she "should" be doing? And why is she doing this forestry work instead of eg tending the pigs and the garden, spinning yarn, preparing food, brewing the beer? If you can answer those questions, you should be fine eg her father/husband/brother has chopped a tree down on himself and is disabled, so can't work and she has to because otherwise they would starve. If you're just making the forester a woman by way of social commentary or to make a feminist point, I'd be a lot more sceptical. People did revolt against the roles imposed by society, but society has a way of getting back at them and usually wins.
Also, how well paid are the foresters? What do they sell and where? Are the other men working alone, or do they co-operate and help each other, or are they employed by the local lord or local saw mill? The better the wage or likely earnings, or the more prestigious the position, the more restrictions will be placed on women doing the work and therefore the worse abuse she will receive for trying to do it. Also, she might not be judged for doing the heavy work if it's that or starve, but she would be judged by the rest of the village if she allowed the female side of things to fall eg if she didn't have the clean house, clean clothes etc.
Basically, do some research into a forester's job and where this woman is living and how she would be paid. And don't forget that a forest was a legal term as well as a description of a lot of trees -- eg the New Forest -- and rights in a such a forest were strictly controlled.
And just as a side issue, being married doesn't mean being a subservient wench wife. Marriages are and were partnerships. Many are unequal partnerships, but that cuts both ways -- the domineering wife is more than just a comedian's punchline -- so there's no reason to assume this woman would be a doormat to her forester husband, especially if she chose her own husband. And the lower down the social scale she is, the more likely that is to have happened.
