Family Issues Support Group
Family issues is a huge range that go from minor conflict to major misbehaviour and even abuse on the part of individual members of the family occur. Whether you feel you are in a dysfunctional family or you're dealing with a very specific issue, this is the place to talk about it and find others who might be going through the same thing.
As you said teenagers have very busy lives. Even parents living in the same house get left in their dust. So it doesn't surprise me that it's hard to get together with them. As to three days to get a reply to a text ... maybe read some of your texts and ask yourself if they are important. Maybe the kids feel like you are trying too hard? Just a thought.
Mother's day is a tough one. Your kids probably feel just as confused. Has anyone ever talked about it? I think it would be nice for them to spend the actual day with their step-mother and siblings but maybe spend the day before with you. It's sounds like you have stayed in their lives which is great. Another option would be to create a special day to celebrate your relationship. And don't be afraid to remind them when your birthday comes around. Something like "so where should we go for dinner on my birthday" would do the trick to remind them.
All in all it sounds like you have made a success of a hard situation. You deserve credit. But always remember that they are still teenagers...and all that entails :)
What's important is the relationship you have with those you love not a day on the calendar.