It's not just Omicron. The baby was put in the icu at birth, and at six months, even if she's "doing beautifully" she likely still has some special health needs. Neither the baby nor the toddler is eligible for vaccination yet.

And honestly, given the sketchiness of the details, it's not really clear if the toddler IS being socially isolated by any reasonable definition. "Very minimal outside social interaction" is a weasel phrase that could mean anything. It definitely doesn't mean "none", though, or LW would've said that.