Paternity Rights

What is the name of your state?What is the name of your state?Pennsylvania
I am the Grandmother of 4 wonderful little souls. My Son recently [last Sept.] moved to Florida to start a better life. Work etc...here was not very profitable for him here. He had been in a relationship with a young woman for the past five years, she having one child to a former relationship and he [my Son] having a child to a former relationship as well. They got together and produced two beautiful twin girls.
They have not lived together for the past two - two and a half years. But lived close and shared in keeping the children. They mostly resided with his Ex so the older children could get off to school together and my Son wanted the children to stay together. Thinking they had already been through enough in young lives. So that's the basics.
Now to the main issue, as stated above he moved to Florida with the understanding that she would soon follow him to Florida with the children. Well as soon as he moved there and started to establish himself, she informed him that she wasn't following him. She started a new relationship with someone and moved him into her [Hud Funded Home]. Now she gets a job and new live-in babysits. (?)
My Son was supposed to get all the children for the summer months, [anticipating the time to spend with them]. Now all of a sudden ex has papers drawn up stated that my son has to return ALL the children back to her possession at a certain date. Well my son then states the Son he had to a previous relationship was not even hers and that he had intended all along [and she knew it] that he was going to bring his son to live with him. Now he wants him back! She is concerned because he has a new relationship living with him and she is now pregnant. Meanwhile, she had a previous relationship between my son and her new guy. That produced twin boys, which she gave them to their biological father, claiming she could not give them the life she thought they deserved.
Well I stated, "why would she keep my Sons boy from him when she gave her own two boys away?" I know she has been the mother figure in my Grandsons life since he was still in diapers. But, this is not right keeping him from a life with his father.
Please give me advice as to what my Son should do next? Can he just come up and take him?

[stealth2]

Your son needs to speak with an attorney - in the state the children live.

And... to be blunt.... he needs to keep his pants zipped and/or make sure he's got a condom on before he makes any more kids.

I feel the same way about making children they can't keep. That goes for the mothers of these children that can't remember to take a pill or simply keep their legs together. Thanks

Are the children still in your son's custody?

He has Paternity rights to Jeremiah [his son] to a previous relationship. My grandsons real mother hasn't been with him since he was two years old. All my Son's leagal papers are here in PA in Storage.

That is NOT the question that I asked. I asked if the children were still in his possession, as in, are they with him now.

No they are here in PA with Ex and He is in Florida.

Now next question. What is this 'legal paper' she had drawn up? Is it a court order or not? And if it is, what does it say exactly?