Yeah, unfortunately, this doesn't sound out-of-line.
A policy for an individual at my job is like $150 a mo. The family plan is $500. Good news with the family plan (I don't know if this is the case for her) is that it covers spouse and as many kids as you have. So, for example, after having our daughter, we added our step daughter to it since she could be covered for no additional cost and saved on child support. So, if she has more kids in the future, there's the chance they could be "free" (if it's this type of family plan).
Additionally, at least it's pre-tax and the additional tax exemption and child tax credit could wind up saving her close to what this will cost. She should estimate the effect on her taxes to hopefully keep in mind when estimating the effect of the baby on her budget.
Also, for comparison, she might want to look into one parent and the kid going on the ACA. If she qualifies for work insurance, she won't qualify for any subsidies, but depending on the plan details it may wind up working out better for an adult with child to get ACA unsubsidized (keeping in mind that then these premiums won't be pre-tax) than what she now has offered through work.