I'll echo the rest of the sentiments here. I'd pay off that $1,200 debt and hold onto the cash. If you had debt, that means your emergency fund needs to be beefed up, especially with one income and a family with two kids (and some wildcard medical issues it sounds like).
Furniture can be extremely cheap if you're patient and willing to put in a little legwork. The computer I'm using to post this is sitting on a $20 thrift store solid wood desk that I bought six years ago. Our couch has survived at least three moves in the last ten years ("inherited"/pushed onto my mom and then me from my grandpa). Our fancypants glass coffee table was about $30 from a thrift store five years ago. Our solid wood dresser was from a thrift store about five years ago and I don't remember the cost, but no more than $50. Our nightstand is actually from IKEA, but I found it on the side of the road five years ago. Our kitchen table was $100 new at Target 2.5 years ago and it's a fucking piece of shit.
With furniture, you get what you pay for, unless you buy used. We have a wonderful thrift store in the area we got all this stuff from. They source of most of their stuff from big estate sales and the like - you're not limited to places like Goodwill/Salvation Army (but they're great too). Craigslist is another option; my (FIREd) dad furnished his apartment 90% from Craigslist a couple years ago and he got some great stuff for almost nothing.
Why do you need a second car? Presumably you're doing fine with one right now, and it's in good shape. GF and I are a household of two, but we only have one car (a 2001 that we put a very unmustachian ~25k miles/year on). She works, but either from home or traveling most of the time. Occasional rental cars in a pinch can be very economical vs buying and maintaining a second car.
And to put our things in perspective, we made about $70k last year.