You could also band your chickens so if she did catch them you could definitely say yes that's mine.
And just be warned that clipping wings does not always work. I had one bird with all her primaries clipped and she still jumped the fence.
Is there a fence keeping the chickens from this lady's yard? I had a 4" strip of fence just to stop my birds from going into the road. It was connected to the house and extended down the road a little ways past where the chickens normally hang out and it kept them in.