Hi. I'm glad you have the willingness to care for these girls, and the relationsip with you grandchildren, to want to serve as their legal guardian. I do suggest you contact an attorney regaridng the best options - guardianship, legal adoption, etc. In most states, a court will have to approve the arrangement. So, even if you do decide to "do-it-yourself" an attorney may be very valuable to you in making sure everything is in place for the judge to approve the situation. You can find more about the attorney locator service on LawInfo's home page at:
http://www.lawinfo.com/.