Is it legal for a neighbor to feed your cats especially after you tell her not to?

If the cats are yours and they are well feed by you then the lady has no right to feed them and if something should happen to one of them like if one of them got sick after being fed by her you could take her to court possibly.

IMPROVEMENT:: If your neighbor comes on to your property and feeds your cats or throws food on to your property to feed your cats then it is illegal...HOWEVER

If your neighbor just puts out food on her own property and your cats venture over on her property to eat it then it is not illegal and there is noting you can do except keep your animals confined to your own property..