over 45

We are older parents of 33, 32 adn 28. We are going to adopt an 11 and 14 yr old sibling group - girls. We have been working toward this for a year and are totally faith based that we should be doing this. I am 55 almost 56 and hubby is 57. Are we insane? Age is all I worry about as we are committed to doing what is best and giving of ourselves to love and connect with these children so they have a forever family...but at this age?