Side Walk councilors do it all the time in front of abortion clinics.
When I was 19 and pregnant, adoption could not be an option for me because the father would not sign the paperwork - without the father’s permission adoption can not be done legally. I ended up keeping my daughter - just turned 14 years old. Not easy.
I heard a call like this on Dr. Laura a few weeks ago and I was devastated. Absolutely devastated for the mother and the baby. She had found the perfect home and family for her baby and was ready to give birth when the ex-boyfriend filed an injunction and stopped the adoption.

Now she’s raising this baby, and totally trapped with him in an on-going court fight and drama. She so badly wants that baby to have the home she had found, and not this nonsense.
We worry so much in this country about preserving a girl’s rights to have an abortion without her parent’s knowing, while simultaneously having to sign consent for her to get a filling. But a girl who makes the choice to adopt her baby out and the unmarried participant in pro-creation can stop it? What in the world???
That makes me so angry. I am sure you love your child immensely, and what I am saying is not a personal offense to you I hope – I just can’t believe how it’s come to this (and also explains a LOT of abortions.) business of men who are not willing to marry women and who use these kids as control. That don’t really WANT full custody and won’t create a family – but wont let the kids go to good families. It makes me so MAD!

(I also wonder how much influence some of these very young men’s families have? Mom badgering them to stop an adoption, so they can be a grandma – on the weekends when it’s convenient of course :banghead:.)
To the OP: yes, you can and should tell a mother about to abort her child she should consider adoption. It’s actually your duty. Whether or not she listens to you is something you can’t control, but suggesting and offering help is the very least you should do.