In college I had a small budget to buy a reliable car to commute and do road trips back home. I bought a VERY boring sedan. Then I got married and bought a NICE sedan (E39), but was costly to maintain (oops). Replaced it with a wagon bc I knew I'd keep the car for 5 years, and it was very likely we'd have a kid during that time. (My wife chose her sedan due to safety and kid-friendliness.). Well, 5 years later we buy a Miata (first gen) bc we held off having kids and we never bought a "fun car". 2 months later my wife gets pregnant. (I probably had something to do with that.). That was 4+ years ago.
So what about the cars? Well, my wife's sedan proved to be unreliable so it got replaced before my son was born - with a larger and more boring sedan. No budget to replace my aging wagon - actually still have it today. (helps that I got the WRX wagon, so it wasn't a penalty box.). I drove the Miata with my 9 month pregnant wife. She fit fine, just took a little effort getting in/out.
Finally was able to "replace" my wagon this year - now nearly 10 years old. Being the responsible dad, I got the BRZ.
. My son loves it. My wife is jealous. Works fine for family stuff now that my son can get in the seat himself, and we're not carrying a giant stroller everywhere. I decided to keep my WRX wagon as a spare vehicle. The extra space comes in handy and I can park it without fear of door dings. But the BRZ is my daily driver.
If you can swing it, sell the truck, get a boring but safe sedan. While your wife is pregnant, your FRS is fine. When your kid turns 2, the FRS is fine. Just gotta get over that short 2 year hurdle. Don't worry - your complete lack of sleep will make considering replacing your car a distant memory from a time when you had 2 quiet minutes to yourself to actually think!