My older two are 18 months apart, IMO, having them closer together is better. Because they were both babies at the same time, I could take care of their needs at the same time. My DS1 loved my DD right from the start. We talked to him about my belly the whole time I was pregnant with her and when she came out, it was like he was waiting for her just like we were. There was no adjustment, that I saw, and I haven't even seen any sibling rivalry...yet! They even had their own language that no one could understand but them, like twins. When DD wasn't able to speak yet, DS1 would interpret for me. When DD was a little baby, I used to feel like I wasn't able to give her what I gave DS, but looking back I realize she didn't get less loving, she got it from a different source, her big brother! Sometimes, when she was hurt or upset, she would go to him...and still does! Of course, they were the only thing I had time for. My house was never really clean and I always had laundry to do, and I was okay w/ that! It's easier to say that now, when it's over, but it definately helped keep my sanity...being able to accept the mess
:. When they both needed me, it was easy to fit each of them on my lap and just hold them. I think that made them closer to each other. They are now 5 1/2 and 4 years old. They are each others best friend, they have the same interests, they get along so well and love each other so much. Every night, they pray for each other first! My third is a different story, he is 3 years younger than my second (I had the exact same due date w/ my 2nd and 3rd!), and I think it's more difficult. The older ones want to go, go, go and I am having a really hard time keeping up w/ the baby in tow. I feel like I kind of held them back for a little while. I also feel bad for the baby sometimes because he's not part of the bond his brother and sister have. Although they each love him so very much. (Sometimes I think I should have another baby for DS2 to have the same kind of relationship!) The baby is now a year old, and it's getting easier to be what all three of them need. I'm sure you will make it work! Good luck
and have fun w/ your babies!