I'll keep it short. It's just been playing on my mind and I would like an outsiders point of view and maybe some guidance..

Me and hubby opened our own salon that we both worked. I had our 1st baby last year and cut back working to only 3 days a week. He works the other 4. 

A month ago his sister decided she wants to train and has started coming in every day. That's fine we have trainees and apprentices all the time some work out and some don't. I personally don't like SIL she is just someone I don't get along with. Recently she has been telling SO what I have said in the shop. Things that are "banter" with my clients and jokes for example my dad gave me a mini bus to use and one said "you should do taxis" and I said "no, nobody pays me petrol money as it is" this was said light hearted and a joke but she made out to SO that I was bitching about how she never offers money for lifts places. That was just one of many where what I have said has been twisted to make me look bad as if I'm bullying her and no exaggeration every day I work I get an earache when I come home over something I haven't thought twice about saying and it's just made me uncomfortable in my own salon. 

My opinion is I built this business and if she were anybody else I either wouldn't have hired her in the first place or would have fired her 2 weeks ago. So I've gone on strike and I am refusing to go to work while she is there. She refuses to not come in on my days and SO feels trapped in a corner and feels like he cannot fire his sister but won't let me fire her either....

AM I The Asshole for going on strike and possibly forcing his hand?