Looks like sis doesn't like boys, even her own brother.
I think partner is a just a term there for who she is living with. I've seen it a lot lately, instead of husband.
Looks like sis doesn't like boys, even her own brother.
Her "partner" could be a man. Just not her husband.
Why are you assuming that the partner is female?
In Europe it is very common to call the man that you live with your partner if you aren't married. I don't think she is a lesbian.