I just wanted to add something...I wouldn't have another child and expect them to be close because of whatever age difference. Being close in age doesn't seem to necessarily mean that they will be close. I think that there are different factors, one being if these are two girls.
My sister and I aren't close, and we are 2 to 3 years apart. I don't remember being close as kids. I remember having to do the same activities and feeling awkward because, for some activities, I was the oldest in the group. I do believe that some of this was caused by my parents.
I met two teenaged girls a few years ago who were less than a year apart. They were 12 and 13 at the time. They had the same activities and were highly competitive with each other and did not get along, partially because they were in the same activities (they might have been in the same grade). And they were close in age (again, this could be different with boys).
I have a friend (woman) with a sister 6 years younger, and they are very close.
So, you just never know. There are a number of factors that cause siblings to be close or not close growing up and as adults, and age difference is just one of those factors.
Just something to think about...
My dad was one of 4. His youngest sister is about 13 years younger than he was... to be honest she is the outcast of the group. She was babied so much she use to say to the other 3 siblings "I wish I was an only child". They all can't stand her. My dad died last month and NO one wanted to call and tell her he died. My dad's brother finally did. At his funeral dinner (which she did not come too
) I asked him how much the other's paid him to call her. I am SO nervous that this one (#4 due in Oct) will be the "outcast" because of how she is...
So far I've lucked out with the 3 I already have
they tell everyone they are all best friends 



The look on the face when I say he was an "on-purpose" is priceless.