Your situation and your daughter’s situation are totally different. It wasn’t a fair question.
Money aside, you and your wife have a committed godly relationship working together to raise your children. You finished school, secured employment, found a home, obtained insurance, and did all the other things responsible mature adults are supposed to do to prepare for having children. Your daughter and “Romeo” have done none of these.
All the support that parents can give a daughter does not compare to the support God intended her to get from a responsible husband. Unless you adopt your grandbaby yourself,** there will likely be constant friction between you and your immature teen daughter about how this child is to be cared for, about who has the right and responsibility to make decisions regarding the raising and instruction of this child. **
At age 15 I’m estimating she just finished 9th grade. That would put her and the baby in your home for at least three more years, whereupon (assuming she says in school and on schedule) she will graduate with enough education to get any job which pays minimum wage and where the most repeated question is, “Do you want fries with that?” If she wants anything better for her baby she’s going to need some technical training, perhaps an associate’s degree, which could have her living in your home with the baby until it is nearly old enough to start school.
And all the while you’ll be dealing with the conflict, “Whose baby is this anyway?” No, what Rau asked was not a fair question. The circumstances do not compare.
15 is just too young. You are not a royal family living in medieval Europe. Open adoption is a much better option for everyone.