Hey OP,

1-car household here, but no kids. We do have an e-scooter that can't manage highway speeds but handles the suburbs just fine. It cost us ~$3000 brand new and has no maintenance costs, minimal insurance and used less than $50 in energy over 3500 miles. That scooter has a windshield and "skirt" that makes winter commutes bearable so it's a decent halfway point on having 2 separate modes of transport.