Does Ben have Cooties or something?

So im so pissed off right now at my MIL (mother in law). Ever since Ben was born she's been a total horder on spending time with him. At first it was a pain cause he was only a day old when it started....but then over the next 3 1/2 hrs i warmed up to her taking him..and then last summer when i was home for about 7 months we had an arrangement that she took ben every tue and thur from about 6-9pm and she got him every other weekend all weekend. She never once cancelled on us, and ben loved it. I loved it too it gave me some free time to myself. While she would watch him she took him to cheerleading events like compations and practices and he loved it. She took him swimming at her sisters. So to my suprise she's been acting very distant since we have come back. The first weekend we were home she took benjamin the whole weekend which was again great. The following weekend she took him for only 1 day over night...well since then she keeps telling us she too busy to take him and she already has plans. She saw him about 2 wks ago when she called and asked if she could take him on a wednesday from about 2-8 which was fine for me...but since then she hasnt asked to take him or anything. So we asked her for the 3rd weekend now to take him (she hasnt taken him in 3 wks) and she said she would take him on saturday but ONLY for the day not over night...I mean what is going on...does ben all of a sudden have cooties or something? This of course being a protective momma bear pisses me off cause im the one who hears him asking if he can go over mom-mom J's and then she basically has no time for him. She even told us when we asked her for this weekend she said she would have to check her schedule...BEN NEEDS AN APPOINTMENT TO SEE HIS GRANDMOTHER? WTF! I mean come on...i just dont see how over the past 3yrs she's been a total horder on him and now she doesnt seem to want anything to do with him...frankly if she keeps this up, i wont let he have ANY time with Haylee cause i refuse to have to try to horde her way in on Haylee but treat ben like he's not important. I just dont know what to do..i dont wanna talk to her about it cause i just dont want the drama....but maybe thats what it needs to come to?