Step Mothers / step kids Please Help!!!!!?

I am a step kid. My dad remarried when I was eight and they had their own kids when I was 14 and 17. So I am much older than my half brother and sister but I wouldn't say that I resent them. I actually think that if I was younger I might have because I would be jealous of all the attention they got and toys and such but being older, I pretty much love them like they were my own children to a point. I adore them and would do anything for them and I even babysit them which is a good perk for my parents :)