Im with porshia, 2 is a good time to switch to a booster at the table.
Mine are 22 months apart and I thought we’d need another high chair but my daughter started wanting out of the chair. We also had a little toddler table that converts into a learning tower. She usually just did activities there but started having her meals there too. So she eats there now and the baby is in the high chair.
I think you'll be fine without one.
Thanks everyone!
By my math, your firstborn will be 20 months, so almost 2 by the time your 2nd will be 6 months and needing a high chair. They may be okay to sit in a regular chair at that point or you could also get a booster chair with buckles, that’s what we did for our first at about the 2 yr old mark