It's been a YEAR since we took her away.

I can't believe you're saying something so untrue. It absolutely does effect them! A kitten is designed to stay with its mother for 6 - 8 weeks and the mother will search for them crying for days if they're removed before this time. Her milk will be at full flow at this time and every instinct will be telling her to feed her babies or they will die. Psychological trauma aside, she's also likely to get mastitis precisely because her milk is in full flow rather than naturally tapering off as the kits get older and are slowly weaned.

On top of that, kittens removed from their mother too early are much more likely to be difficult adults as theyve missed out on their mother's care and discipline at an important learning stage in life.