I have a daughter in the same range. Though it’s very difficult at times, we view her as a child. She lives with us, though she goes to work and what not. We will not let her enter into a romantic relationship, and are fairly forthright in explaining why in a compassionate way. She gets frustrated at times, but usually she is thankful that we are there as her parents. The fact is, she is not a fully developed woman capable of responsible marriage, or the having and raising of children. She is about at 10 year old girl, in spite of her 25 years of life. She also, always will be. We’ve had this confirmed by many doctors. It is our duty, as her parents to protect her.
Please seek some advice from some professionals, but I think you might find that perhaps she should not be living with her boyfriend and having sex. Your issue might not be whether she should be using contraception, but whether or not she has the ability to be married and be mother. If not, then perhaps she should live at home, and be supervised. She might not be as old as you think she is, if she’s in this IQ range.
Anyway, I’ll pray for you and her, as I can certainly relate to the problem. Please discuss with someone from whatever faith you may be involved in, and perhaps look into guardianship, etc. Otherwise, you are pretty much taking the responsibility upon yourself for any children she may conceive and bear. I know that if my daughter had a child, that would be on my wife and I. It would be another child for us. Not a grandchild.
Either way…contraception is not the answer. Even for the low IQ, a willingness to have sex, or the consent of the parent to them having sex is also saying yes to God to have the wisdom of whether or not to produce life from any resulting unions. It’s not our choice.
My deepest prayers,
Peace,
Steven