Need Advice- My stepdad's wife

CVsanger

So, here's a little background:

My father passed away in 1999 when I was 14 years old. My mother remarried a man named Joe (my stepdad) in 2006 and passed away very suddenly in the beginning of 2010.

My brother and I made a big effort to keep my stepdad in our lives as he has no children of his own and the rest of his family lives in Florida. We continued including him in holidays and birthday celebrations. And he was invited to my Las Vegas wedding in March of 2012.

At my wedding reception, my stepdad met our best man's mother and they exchanged phone numbers. I wasn't extremely pleased. Needless to say...they got married in September of 2012.

I announced my pregnancy to my stepdad at the end of July (2 months before their wedding) and his girlfriend was next to him at the time. When I told him about the pregnancy he congratulated me and she said: "I'm so excited to be a grandma!"

I was more than a little flabbergasted at her response. Really? I hardly know you. My MOTHER is my LO's grandmother, not you. <sigh> DH thinks I'm being a little oversensitive, but I have a real problem with this. With both of my parents being gone, I really hold the names grandma and grandpa in high regard. Don't get me wrong- my stepdad's wife is a very sweet woman, but I'm not ready to have my child call her grandma.

I've thought about it and think the LO could call my stepdad "Grandpa Joe" and his new wife "Miss Linda." DH thinks this will cause some drama. How do I make this happen? Do I talk to her about my feelings on this (even though we don't really know each other well)? Or do I simply instruct LO to call her Miss Linda when he's old enough to talk?

Or am I simply being oversensitive like my DH thinks I am?

TIA