I can only tell you that my daughter-in-law went to the Mikvah as she entered her ninth month of pregnancy(which is a popular segulah in our neighborhood for an easy delivery), and a childless young woman was the next woman to go into the Mikvah after she came out (which is another segulah that is popular here), and within two months, the childless woman was expecting and delivered a healthy baby later that year. She had been trying for a while with no success. We coordinated the two tevilos to coincide with my DIL’s beginning of the ninth month and the childless woman’s specific leil tevilah. Whether or not this segulah is an accepted one by the frum velt at large, it certainly had two great outcomes, an easy delivery for one and a pregnancy for another woman. Both women delivered boys.
Aside from this, daven with all your heart for the childless women you know. Take two childless women and ask them to each daven for the other one and they will B”EH both be answered.