My mom's parents were born in the late 1870s! Do the math...we're late reproducers. They were in their mid to late 40s when my aunt and mom were born (back in the mid 1920s). My mom had me in her mid 30s; I had our son at almost 37 and my husband was 44. I guess my mom and I were early bloomers in the family tree. : )
The things I would ask yourself are varied...
1) Do you have the energy for two little ones? (If so, you'll have a ball with them. They'll keep you young.)
2) Do you have a history of depression other than PPD? (If so, perimenopause can mess with your emotions as much or more than pregnancy and life. Just be aware of that.)
3) Are you prepared to be 60+ with high schoolers? (It's happening more these days. However, our 12-year-old is already complaining about how old we are...achy knees, more established in work, "boring", no cousins his age).
4) Are you prepared to deal with the outcome if your new baby has health issues? (If this happens, have you thought through your actions or choices if something complicated arises? Would you terminate the pregnancy or not? This is something you and your husband need to think about so you are prepared, even if the situation doesn't arise or you choose to not do anything.)
5) Are you interested in doing fertility steps if needed? (If so, how far would you go with that? To what extent are you dedicated to having a birth? Secondary infertility is common at this age. We were never able to have a second child which feels like a loss but something we have basically come to peace with.)
6) Is adoption an option? (I know many people who have taken that route. Some don't for fear they may not love the child as much as one born to them. Sometimes that happens, but more often than not, the adopted baby is loved to the fullest. Babies and kids have a way of doing that to you!)
My nieces and nephews on my side range from college-age to 40. My husband's twin brother has a 27- and 29-year-old; his sister has an almost 40-year-old. His twin razzed us when we got pregnant saying, "We're almost finished, and you're just beginning! Nah, na-nah, na-nah, nah, nahh." We're hitting adolescence while their kids are getting married or having a kid already.
We're okay with that, but there's no doubt we're more tired than younger parents. But, as many have said, we're more patient.
Plus, we've had more interesting and varied life experiences, prior to our son. For instance, my husband worked overseas and traveled so much, he had to have extra pages added to his passport. He is able to give real stories to many of the places our son is studying in school. It makes these places come alive for our son! It's fun sharing stories with him of our lives before him. (Sometimes, I think he wishes we still did some of that stuff now.)
You may feel like not many older parents are out there, but they start coming out of the woodwork when you have kids. If not in your town, certainly you have a resource here. It's not next door, but it provides some wonderful support. If there is a parents' group in your town, you may find more older moms there.
So, I can't tell you what to do. But at least I can provide some questions and thoughts to help you think this through. My husband and I did some fertility but then stopped. We thought about adoption but chose not to. We still have pangs of wishing for a sibling for our son every once in a while. But we also are able to give him our all because of him being our "only". He has friends over all the time to provide plenty of exchange with other kids. And he has us, all of us, for better or worse.
If you go for another baby, I hope your body cooperates. Good luck! Happy decision-making!