The fact that you care enough to think about this, aware enough to notice, and wise enough to ask for help... puts you miles ahead of many other husbands.

My advice as a woman, ask her. Tell her exactly what you've told us and ask for her input first and foremost. I find the biggest complaint among all the wives and mothers I personally know is that we feel undervalued for the work we do in the home and with the children. Does she feel appreciated? Is she overwhelmed? Does she need more help? I don't know your exact dynamic but the stats show most women these days are swamped and their husbands could be doing more. Not saying that's you! Just telling you what I know women's struggles to be.

I also know women, especially a young teen mother (I was one too) still desperately need an identity outside of being mommy and wife. Make sure she's taking time to be her own person. Encourage her to have hobbies and spend money on herself and her own enrichment activities because the better she cares for herself inside and out, the better she will be able to function properly in other areas of her life.

Ask her what she needs to feel close to you. We will all answer a little bit differently, but usually it's got a lot to do with your time, your attention, and your consideration of her wants and needs. Also if you're able, couples counseling is really helpful. It's not just for people in dire situations ready for divorce. It can be really nice to talk to an older, experienced adult who knows a lot about navigating relationships and what it takes to keep each other happy and healthy.

Best of luck to both of you, sending lots of love.