Sons grandparents.

I’m not sure where to post.My sons dad wants nothing to do with my son, but his mom she said they want to be in his life and even offered a DNA test. So I said okay bought the DNA test, so I dropped the first one off in her mailbox she claims she didn’t get it, then I had FEDEX deliver it and she said she didn’t get it. I got an extra kit just in case she said that. I know she got it cause tracking said it was sent! Anyways when I came and got some dna i approached her with the test. As she’s taking it she’s telling me how she doesn’t want her son to feel as if she has betrayed him. I almost lost it! This lady had lied to me telling me she’d be around and she’d help and anything I need to let her know, but when I’m texting her asking about the dna test I get no response, she didn’t even know his name! She didn’t ask, and when I said she could see him she didn’t say anything. She told me yo put her son on child support, told me to have him served. As she’s swabbing she’s also saying we wanna be in his life, etc etc. What would you do? Should I let her see my son? I feel she’s excusing her sons actions not only that but she OFFERED ME A DNA TEST then lied not once but TWICE. I understand her loyalty to her son. But my son is innocent in this. She kept on saying I love my grandkids all the same, I wanna be in the babys life if he is. But at this point I feel she’s betrayed my trust.