Create them all as adults and then use the aging cheat (or a hack) to age down two of them. You'll need to age them down to toddlers and then let them age up. That avoids problems.
Are we sure that definitely avoids the "
dangling SWAF" issue, though? That's the one I'm afraid of.
I've only seen it
in conjunction with deleteallcharacters, but then again, Pescado only named it on May 12th, so maybe we don't know everything about it yet...
I've made families this way before, and I usually check the neighborhood file for any weirdness, but no, I don't know for sure that all problems are avoided.
However, this would not be a "dangling" SWAF problem, would it? That one's related to sims inheriting SWAFs that don't belong to them. The sims (in this case, just the child) would have its own SWAF entry.
Having toddlers or children get LTWs or weird (age inappropriate) wants might be a dangling SWAF problem, but having a child or toddler with an LTW due to de-aging would most likely not be the same type of problem. Not necessarily harmless though....
Someone should do some experimenting and find out for sure.