When's too soon for baby to go far away?

So my daughter's grandmother ( her dad's side ) had asked to take Olivia out of state ( only an hour or so away ), she'll be 7 months old in 3 days, and I've never really been that far away from her. I told her no, because I am uncomfortable with it. Accidents happen with no one being at fault. Am I over reacting ?

    I've known this woman for maybe two years now, she's only come around when it's convenient for her. And she has been around Olivia maybe 4 or 5 times since she was born 7 months ago. She doesn't know what my daughter likes, she doesn't know what makes her feel better, she doesn't even know what size clothes she wears. It would be like leaving with pretty much a complete stranger, to a completely different place that seems really far away to me ):. I guess I just stress out because it's been only me taking care of her since she was born.
    About Samie McKenzie
    Born: West Salisbury, Pennsylvania
    Current: Somerset, Pennsylvania
    Birth: July 13
    On Moms.com since: Mar 30, 2014
    I am a 19 year old single stay at home mom. I'm open to meeting new people and I'm pretty easy to get along with!