Do I have to get my sister a card or something for Mothers Day?

My sister and I share custody of my son. I hate it. I'm a single mom. Long story short my family tricked me into it. At first it was to help out here and there. Then it was to help out with medical bills. My son is ADHD. He has a lot of bills for medicen and counsling. Dental. Braces. Then it was to pay for sports stuff and swim lessons. Then it was to change his school. The one by her house is better. He stays with her half the week then me the rest. Then they said I needed to sign a guardenship paper so they can claim him on their taxes since they were paying for most of his care. Well now she has taken total control. If feel if I do anything to upset her or my family, they wont let me see my son anymore. They did it once when I was dating someone they didn't like. Things are kind ok now. Do I have to reconize her on mothers day? She is not his mom or ever will be. Someone suggested a thank you card. If I don't I feel it will fuel the fires again and make her mad. HELP
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Your family sounds a little too controlling...nonetheless, you should still let your sister and family know that you appreciate them helping you out...it doesn't necesarily have to be a mother's day card...since you are the mother
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