I have probably unpopular opinion but still. The reason they have suddenly drifted apart may be due to the fact that they have been together for 13 years and then had a child which makes life way more different and complicated. Have you considered that the drifting apart thing and not working well together is just because you suddenly have a toddler. Having another child may help you two to find the spark again and enjoy the relationship. I mean 15 years is quite a lot to just give up, every relationship has difficulties and days-weeks when you think if everything you are doing is even worth it. I think that the grass isn’t greener outside your relationship. I don’t know the reason why you suddenly feel like you two aren’t compatible if you have been together 15 years, you aren’t getting younger and it is really nice to have some stability in your life and a partner who really knows you and all your quirks.

Have you tried couples counseling? It is totally possible to get close again.

I think that for some reason after being together for 12.5 years you decided that you want to have a child together. Then came the pregnancy, crazy emotions and the covid pandemic as well. Now you are considering a second child and I think that the reason you are doing so is that neither of you really want to give up on eachother and want to stay close. So really, give it time and do not rush anything:)

Ps! English isn’t my native language so sorry if there are mistakes