Coming out over IM

I haven't mentioned Jenn much before. Jenn is a good friend I've known since 8th grade. I am also good friends with her brother who is the same age. I even know her parents pretty well. Jenn's mom is the sweetest lady who knows everybody. Her mom always says that she can see Jenn and I marrying in the future. Her mom was so sad when I didn't ask her daughter to prom in high school. I only bring Jenn's mom into the story because Jenn and her mom are VERY close, so she'll probably hear.
Jenn is just about the most caring person I know. She cares so much about everyone, wants them to be happy, and I can't ask for more. I can tell Jenn anything and am comfortable in doing so. Jenn is pretty Catholic and she doesn't have any gay friends or anyone that I can think of so I'm not sure what her response would be.

I am possibly ready to tell Jenn. The question is how. She is close to her mom and brother, both, so I know that they'll probably find out. I don't value her brother's friendship as highly as I value hers I guess I can say for these purposes. I am sure Jenn's mom will find out and I am not sure I'm comfortable her knowing so early in the process. I guess all I can do is beg her not to tell when I do come out. Her mom now lives in Arizona, so worrying my parents will find out makes it a little easier.

But the question is how to tell Jenn. She'll probably be supportive, the huggy, emotional type. Whenever we see each other it is always with a group of friends. ALWAYS. NEVER are we alone. We can only see each other during breaks, so it is always a group thing. Plus, she is permanently bound to our friend Cherry because she stays at Cherry's house when she is in the area. So being alone is out of the question.

We only talk to each other online. We're not the phone type. I think I've spoke to her maybe 5 times on the phone in 7-8 years. We instant message each other online at least once a week. She tells me about what's going on with her mom, grandparents, brother, dad, school, work, and really we don't have a hard time opening up to each other. I think me calling her to come out would be awkward unless I were in say a depressed situation where I have something that has really been bringing her down lately and begging for her sympathy, which I don't want to do. I know just me calling would be out of the ordinary and I can't just say "Jenn, I'm gay".

I think online would be much easier because it is a medium we regularly use, so it wouldn't be AS awkward. I don't really want to come out online because it is much more impersonal, but I don't see us ever being alone where I could do it. I am not even sure how I'd bring myself to do it online. She doesn't tell me about hot guys or anything like my coworker B does when we chat online. No... we just talk about what is bothering each of us, stuff like that. Perhaps that could be a way to approach it. She asks me how I am and I say I'm down. She'll ask why and I can explain as long as she doesn't tell anyone etc. etc.

Hm... decisions decisions...