First off: Awesome accent! (Well to you there isn’t one lol)
Women in general tend to have knees that bow inward just naturally. It isn’t inherently bad, but it can be depending on posture, weight, height, etc. It’s not noticeable for me when I squat, but sometimes when I’m just idly standing it’s noticeable in my right leg.
It also looks like your wife has flat feet. In which the inside of the foot is pronating quite a bit to where it’s also pulling her leg and knee in. I could be wrong, but that’s what it’s looking like. I’ve got hella flat feet as well, and I also have this issue if I find I’m not correctly in position when squatting.
Someone mentioned it above, but taking her stance width in a bit would definitely help. I would say to keep her feet out, but not too too much. Also supplementing In adductor work wouldn’t hurt either. If it’s only happening with one leg, you could also try mimicking an arch with like a band support that has an arch cushion, or (cheap version) put a band around her foot and put like a thin sock right where her arch is, or is supposed to be just to keep that ankle from pronating so much.
OR an even cheaper version, go for a flat shoe, lace it up fairly tight, and just shove a good bit of cotton puffs or a fluffy sock where the shoe starts to curve to fit her arch.