I definitely prefer using either 'titles' or terms of endearment when referring to elder family members; I just don't feel right calling people by their first names when they are my aunt, uncle, in-laws, etc. My mom is my Mommy and always will be- she is everybody else's Liz but she's my mom- mine and my brothers, and ours only. ykwim? I do call one of my aunts "Dee", but that's a family nickname and I would never call her by her real name (Kathy). That's just my preference though.
Most of my nieces and nephews on my in-law side (I don't consider them just 'my husband's nieces/nephews') call me Nic, but they're slowly getting used to saying "Auntie Nic". Honestly it bothered me that they only used my first name (they do call all their other aunties/uncles-by-marriage by their titles) because it made me feel less a part of the family.
Most of my nieces and nephews on my in-law side (I don't consider them just 'my husband's nieces/nephews') call me Nic, but they're slowly getting used to saying "Auntie Nic". Honestly it bothered me that they only used my first name (they do call all their other aunties/uncles-by-marriage by their titles) because it made me feel less a part of the family.