I'm sorry to hear your sister was able to find you with your defenses down. I doubt she planned it, sounds like that is the way she is, perhaps also from the family dynamics?

Ok, so you pick yourself up and move along.

Recently someone caught me with my shield down also, and though I mildly enjoyed the tit for tat exchange, it was beneath me. This person, well, it's normal for the person who instigated it and because of that I guess they are good at it? Much better than I since I don't engage in that behavior generally. Anyway, it wasn't a good thing for me, and tends to have a domino effect for me. I had to be conscious of it and stop.

Think through this now, if you can. Or, when you are fully able. Think through it, start to finish. Try to find a better way to handle such a situation. Over the course of many such "failures" you will find that you are doing better, and that eventually you won't have hardly any trouble at all with family guilt and behavior.

I think, while you're thinking... decide the reason WHY you cleaned out her gutters. That might lead to an AH HA moment that you can learn to prevent in the future.