Opinions?

So my husbands grandma(whom, he rarely talks to, and she not once has tried to talk to me, but instead bad mouth me to my husband) but now I'm supposed to send them a baby shower invite??
It's really frustrating and makes me really upset that they're doing that..... Out of 4 years, going on 5 now, they not more than 5 times have talked to me.... Or even tried to. 
Am I over reacting, or is to be upset perfectly normal?