Newbie.....dealing with a MLC'er....

[Amy40]

I would tell her she needs to plan ahead if she can not stick to the prearranged schedule.
She should not think she can call/text at her whim and TELL you she is picking up your son.

I wouldn't let him go tomorrow.
Let her visit with him at your parent's house if she wants to see him.

You still have no idea what she does with him or where she takes him.

In my opinion she owes you some answers before she is allowed to take the boy anywhere - especially since she blew him off on Saturday.