I like this woman who is older than me, and I was just wondering what age difference is too much for anything to happen between us?
Legally? Socially? Logistically? Practically? Legally = make sure you understand the laws in your area. Common rule of thumb is that if you're under 18 don't mess around with anyone over 18. Socially = you and your friends are at a certain point in your lives. The things you enjoy doing with your friends are likely not the things she and her friends like if she's, say,30. Are you okay with having two separate social groups and the maintenance required for both? Logistically = if she's older she probably had a car, an apartment or home, and all the trappings that go along with adult life. Her schedule may be different than yours and that can make for a more challenging relationship. Practically = I think it is difficult enough to have a successful relationship period let alone one where two people see in very different stages of their lives. If you decide to move forward with a relationship with this person you may have more cards stacked against you than if you were with someone closer in age. That doesn't mean you should give up just understand the battle. Good luck!
There is not such thing as too old really...but in terms of difficulties, the older the more challenging to make things work... But hey, is not about how easy things are, is about how happy you are. Also this
At 16, more than 3 or 4 years is almost certainly going to be unhealthy. Beyond that, the experience, life situations, and power dynamics will make for a very unbalanced and unequal relationship. I'd think long and carefully about this, because it's really easy to get into relationships like this that can end up really limiting your own independence, and the development of your own social and psychological development and self-sufficiency. If it's only a couple of years difference, then it shouldn't be a problem. Any more than that, and you're really asking for trouble.