I don't think we are going to be moving away from a society of individuals anytime soon, and honestly I'm okay with that, and even prefer it in many ways. There is a reason people move away from the small towns they grew up in. I don't know if I have an answer for society as a whole, but I have found ways to "make community" and evade isolation as a stay at home mom in our modern world.
First, I've found that a little mindfulness meditation goes a long ways towards removing the feeling of "other" when talking to people I encounter during my day. Wherever there are people, there are friends. Maintaining a feeling of shared humanity virtually eliminates the pining I used to feel for needing to see my old friends often (many of whom have moved away, or don't have kids, so our time together is spotty at best).
Even though it can seem like a frivolous expense, frequenting your neighborhood cafe is a great way to meet people. I spent a couple years as a barista in a small neighborhood cafe, and was moved to tears several times by the beauty and quality of community building that space seemed to provide. My boss used to say, "Saving the world, one cup at a time." And I totally agree with that sentiment. Being in the same place at the same time day after day is key. Friendships aren't hunted, they form organically by shared experience, time and space.
I never thought a box store would provide a sense of community, but our local Barnes & Noble has a train table that seems to have united most of the families with toddlers in our neighborhood. Being stuck in the kids' section with other parents has inspired many conversations, and even spontaneous book discussions. One B&N employee told me he runs into customers just working in his yard, and the kid's yell, "Hi book guy!" as they walk by.
In our neighborhood, several families have started restaurants and neighborhood kids play with the owner's kids while they wait for dinner. I've been really impressed by the energy the "family first" pizza place has brought to the neighborhood. Their hours reflect what they are able to offer and still function as a family, and not surrendering themselves to idea that you have to constantly accessible to stay in business. They often have to close early because they've sold out of pizza, so I think they'll be okay, and I'm proud of them.
What we really need is policy reform that respects mother and child as a single unit and provides a means of survival for the first 2-3 years, rather than 6-12 unpaid weeks. A pump isn't a baby, and even if you have a progressive work place that supports pumping, supply can still suffer because the whole operation works best with pheromone feedback between mama and baby. I think not being able to find much work after my son was born was actually a blessing, even if it sucked in the bank account department.
Creating a small scale gift economy or barter economy can bring people together too. Share your harvest, talents, and time. I offer my garden up to my neighbor to pick whatever she wants, and barter lip balm and lotion bars whenever possible. I also offer a barter option for clients when I get real work.
I haven't tried this myself yet, but I often spend Sunday preparing meals for the week, and I know some people swap a portion of what they are making with other families to have more variety.