Hi. I'm due to get married next year. But my sil I currently having nothing...

I wouldn't invite her to the hen - but maybe to the wedding. If she decides to no show up, that's not your fault. If you don't invite her and she's expecting to be that could cause more issues.

Yes i would invite her, as in the future she can't say that you did not. It is then her choice if she attends x

I'd invite her to the wedding, but not he hen do. If things are fine between you two before the hen do, then I'd invite her, but I don't thinks there's need to otherwise

Yeah, i'd personaly invite to both just so you know you've tried. X

I'd invite to wedding but not the hen do. Like you say you've done nothing wrong and you don't want her to try and use it in the future. If she decides not to come that's down to her x

I'd invite her to the wedding, at least way it can never come back on you that you didn't try. but maybe not the hen.

I would invite her to the wedding so you can say you tried but not bother with the hen do x