Would it be possible for me to re-lactate?

After a month I don't think it could be possible to start lactation again. I do find it a little odd you weaned your son so he would be off the when your new baby gets here but you have no problems feeding this little girl? If you're really bothered by formula feeding her look for milk banks (at least that's what I think they're called) in your area, which are organizations that take donated milk for women who cannot feed and need it.