I haven't seen DD is weeks

Glammananna is right, your daughter knows you love her and will be there for her Tutu It's a given , life is just busy for her at the moment. Don't worry unnecessarily.

This must be so hurtful for you, you have obviously always know this could happen, but that doesn’t make it any easier.

You will always be her mum no matter what, you brought her up and loved her, Probably once the novelty of finding her family wears off a bit, things will get back to normal, in the meantime, try not to appear too needy. Just be there waiting.

I think you should say to her that you feel sad not to be seeing more of her and your DGS. Sometimes it’s just a case of time whizzing by and being busy.
Offer to go to hers, even pop in - you are her Mum! Offer to treat to coffee somewhere you know she’d like. Be proactive. When you see her, arrange when you will next see her, be honest with her.
Could you get involved in taking GCs to a regular activity? A friends parents treated GD to horse riding lessons which friend could never have afforded, either cost or time...GPs then had a regular slot to see GD and their daughter as they picked up and dropped off, popped in for cuppa, etc.

I agree although it is upsetting. Our DD only lives 15 minutes away and we rarely see her. I thought we were close but it hasn't proved to be the case.

I don't for one minute think she is deliberatly not getting in touch with you and your OH,life will be so busy for her with a young DS and her work schedule.
She knows you are there for her no matter what and sometimes us mums are just at the bottom of the list through no fault of our own.

Whoops pressed the button too soon
I m sure you haven’t done anything to ‘deserve’ her indifferent treatment she may be very busy and juggling work and other life things why not invite her and grandson to lunch and hopefully she will come along and you can have a good time again

This must be so hurtful when you have put in all the hard work over the years The same happened to a friend she brought her daughter up single handed with no help from the absent father Then at age 17 the daughter ‘found’ her father built up a relationship and moved out to live with him as she wasn’t too fond of any house rules in her mums home We lost touch over the years so I don’t know if it ended happily or not I rather think it probably didn’t My friend was totally devastated at the time
I m sure you haven’t done anything to ‘deserve’

Probably nothing at all Tutu (ref last sentence) but she’s obviously finding it difficult to get everything done in the time available. Let her come to you (and she will) and don’t let on how much it hurts - as mothers, that’s our lot sometimes!