Domestic flights allow check-in up to 30 minutes before departure, so this connection would give you up to 1hr 25min from touchdown to domestic check in. If you were travelling with hand luggage only and willing to hustle, I would consider it safe enough. With luggage and a small child, however, I think you might have a better day if you give yourselves a more relaxed plan.
There are several flights per hour from HND to CTS. I would suggest a flight sometime around 9:00am.

JAL and ANA offer some promotional fares for visitors:
https://www.ana.co.jp/en/us/plan-boo...special-fares/
https://www.jal.co.jp/yokosojapan/japanfare.html