I happened to be seated next to a lovely young lady on a flight recently. We hit it off really nicely, talked a lot during the flight, and she signaled she was single which is nice because I am too. She seemed to really like me and of course I liked her a lot as well. She lives in a different part of the country but she travels a lot on business and goes to where I live several times a year. 

When we landed I conjured up the courage to offer to give her my number so I could see her when she comes to town (so I could show her around etc), and she eagerly texted me on the spot so as to exchange phone numbers. I texted her something funny the next day and she responded right away and we've been doing that from time to time.

There is one problem however. I am in my early forties but I look much younger whereby people who don't know usually think I'm in my early thirties. I estimate she must be around 32 years old, 35 max. As I recall I wasn't able to work anything into the conversation that might signal the age difference. I am very concerned she might feel deceived and lose interest or something when she finds out about the difference.

How do I signal the difference without her being mortified and thinking I'm some creepy old dude hitting on her? I mean, a lot of women would have no problem with a ~10 year difference, but I imagine many would.

I should mention I am fairly inexperienced in these things.

Thanks in advance!