One website I found to be helpful was meetup.com. You can enter a zip code and the type of group you're looking for (for example, stay-at-hom moms) and it will list groups in your area. I found a group that was for moms in my housing development and have attended some fun playdates.
Another option that may be good for you is MOPS (Mother of Preschoolers). These programs often meet at churches twice a month. The moms do a program while the children are watched separately. If you do a google search for "MOPS" and the city of your choice, you will probably find multiple options. I searched "MOPS McKinney Texas" and found MOPS programs at three different churches.