Leigh R. is right. I also agree with Theresa ")N.
"I just don't understand why she would find it necessary to tell a 10-yr-old she forgot it was her granddaughters birthday."
- MIL wasn't thinking.
- MIL thought being honest was better… to explain why the call came so late.
- MIL didn't realize GD would be devastated (if she did, she would not have admitted the truth)
- MIL hates your daughter (doubtful - so you can blame human error)
You might need to forgive your MIL also.
I know your daughter is little and she was hurt. Remind her that she is blessed to have a grandmother. Remind her that people are not perfect. Everyone makes mistakes!!! Forgetting was a mistake. Remind her that her grandmother loves her SO SO much! Your MIL sounds distracted. I'm very distracted. My family gets angry with me. It's NOT personal against them. It's MY issue. I've got lots of balls juggling in the air at once and if one drops (or "oops I forgot") family gets angry with me. They are right to get angry. Everyone needs feedback. I appreciate the feedback, but it has to be done in the right manner.
Don't go to MIL angry "you hurt my baby." Instead approach her with a friendly, loving heart and explain to her she was so hurt (but don't blame MIL - she'll sense it a mile away). See if MIL can give her a little extra attention (TLC) on Thanksgiving.
Can you be honest with you MIL? Can you tell her that it's a bit strange she reminds you for WEEKs about the other birthdays and she forgot her granddaughters. Hopefully this will help her realize she really needs to step up and give her granddaughter extra TLC this year.
I think you should face this head on and deal with it so it doesn't happen again. It's difficult for a 10-yr-old to express themselves sometimes, so you should do it first, but very tactfully. No anger on your part. Do it in the spirit of "hey, we have a little problem here (all smiles and a loving heart, you want the best for both of them, not just one), what can we do to make it better?"
Do you send MIL lots of pictures? I send mine. MIL loves seeing them. That helps to keep my kids fresh in her mind. Next year, spend a few weeks ahead of time calling your MIL to remind her. :) She would probably appreciate it! I forget relatives birthdays too!
Your daughter: don't nurse her feelings of resentment. They can lead to bitterness, envy (of cousins) and feeling sorry for herself. Nip that in the bud! Build her up! Help her to overcome this.
I have a sister and for her birthdays are a big deal. She takes it very personally how people react to her birthday (if they forget, if they call or not, send a gift or not, etc…) Me? I could care less. If people remember, yeah that's awesome and sweet, but I don't hold it over people's heads. That's not fair or right. And I remind myself every day how grateful I am for the things in my life. I don't need 1 present a year to feel good. Every day is a blessing from God.
Knowing my sister, I now know to send her LOTS of gifts (little things, silly things, heartfelt things… AND flowers delivered to her door because she is in another state) and she is so grateful and it means a lot to her.