Denise, I would have to agree with everyone that you have the skills to be a successful wedding photographer, but there are a lot of other things that are involved in doing a wedding besides just the shooting. First wedding situation I was in, I was asked by the FOG to just shoot the reception as they had hired a pro for the formals and the wedding itself. After that, he asked me to photograph his next three children's weddings, but he did the formal portraits because he was comfortable with that and he had all of the equipment because he did that also. I did everything for a friends wedding last year and it went off well. Being the only source of photography for the event is a lot to shoulder and I would recommend renting a backup for that situation if you do decide to do it. Your 7D will be perfectly fine for shooting the wedding, so don't worry about upgrading gear.

I would definitely let the couple know of your shooting experience regarding weddings and portraits in general. Have a time which you can set up a engagement shoot with them and see if it is your cup of tea. If it is not what you were expecting judging by what you get at the engagement session, then I would decline. If it goes well and you are happy with what you shot, then I think you should go for it. I would just set up the engagement session sooner than later so if it doesn't workout, then they still have time to find someone else.

I haven't continued taking wedding jobs because I didn't want the liability since I didn't have a business LLC or Corp set up. If you do take the job, make sure you have a contract to cover yourself. I am sure others here have more knowledge about that then I do.

One last thing, make sure you know what kind of service it is going to be (judge, catholic, lutheran, etc.) because they are all different.