Family opinions about engagement?

[Murrin]

My boyfriend and I will be celebrating our 3rd anniversary soon, and both of our families have decided that "it's time" to get engaged. The problem is, it's not exactly their decision! We both come from families where people usually marry young - and divorce a lot. We've spent a lot of time focusing on our needs as a couple and decided not to take major steps just because we've been together for one year, two years, three years, etc. but because we love each other and we'll be ready when we feel we're ready. It seems like so many marital problems begin because people feel pressured to take steps, and we'd rather spend this time getting to know each other than planning a wedding - yet.

Still, we're close to our families and it's rough to hear their opinions - we must not really love each other, we're not doing things right, etc. We know they're wrong, but we want their support. What should we do to explain this to them effectively? Did you and your fiance/spouse wait like we are?