For context, there's 3 in our house. One small child.
We swim twice a week, husband runs.
Daughter has school uniform and whatever clothes she wears, husband has work clothes and lounge wear etc he re wears his joggers etc for after work for probably a week, and wears the. T-shirt a few days.
We use a minimum of 21 pairs of underwear, 3 bras, 21 pairs of socks, a dozen or so tops, a couple of hoodies/jackets/cardigans, 12+ trousers/shorts/skirts, 3 bath towels, 1 bath mat, 2 hand towels, 3 tea towels, 7 wash cloths (kitchen ones) each week. Swimming costumes, and towels, a set of bedding.
And every so often we have to also wash coats, hats, blankets, cloth bags etc.
We do load probably every other day, sometimes every day.
I just don't see how she can squeeze an extra person's stuff in to fewer loads 🤷