To have a friend, you need to be a friend. The advice to invite people over is a good one. Engage in casual conversation with ladies whom you see after Shul. Go to the park with your kids, if they are age appropriate, or join some other group with them that encourages moms to meet. If you can find the time in what I am sure is a very busy day between home and outside work, join a ladies’ gym, if you can afford to, or get your nails done in a salon frequented by frum young women. personally I don’t go for manicures, but my friend does and she meets new people ALL the time.
Depending on where you live, if you go out walking for exercise, you will often see a number of women doing the same. If all else fails, strike up a conversation in your local supermarket, pediatrician’s office, or even Dunkin’Donuts (so many kosher ones out there). Take your little ones (again, if they are little) to the local library when you are off from work. I am a Bubby and I ALWAYS see frum women there with the children or aineklach. I have gotten into many enjoyable conversations that way.
I realize that not all frum women will make use of ALL these suggestions, but find your comfort zone and use it to make friends. I wish you hatzlacha rabbah.