My daughter in-law has gone to her apartment complex manager and told her that I struck her in an effort to encourage me from being able to see my son in his place of residence. This is completley false. Can I or should I press charges as this is not the first time she has lied to this extent for her own end.

I assume you are in the US. You don't "press charges" for slander, as it's not a criminal offense. What you can do is file a lawsuit, claiming that your reputation has been irreperably harmed. If you really think you have a case, then go talk to a lawyer. However, for family matters like this I would suggest that filing a lawsuit may not be the wisest course of action - after all, in essence you'd be suing both your daughter-in-law and your son (since any judgment you win would affect him as well), and you might as well give up on ever seeing him again.

That makes perfect sense. Thank you so much for your reply.

Another point is that you need to show that you have been damaged. And this will be very hard to prove.

Have you spoken to your son about the interference your D-I-L is giving you?

That makes perfect sense. Thank you so much for your reply.

That makes perfect sense. Thank you so much for your reply.