Initially, I'd try your luck on-line. Ancestry.com has a lot of public records available on line through their subscriptions. I actually found many for both a William G. Crawford and an Emma L. Stroup in Pennsylvania, as well as for Alma Crawfords. Some may refer to your ancestors. If you had given me dates of birth and death (at least approximately), I could have done a more accurate check. Ancestry offers a two week free trial subscription. You might try that. After that you would have to actually chase down actual records probably in the Butler County records and in other archives. Good luck. I continue to be happy to help in any way I can. Regards. And best of luck in your researching.