5 year age gap

Ra
My first is going to be 5 in a few weeks and my second is due in November. I'm wondering if anyone has had this age gap and what are some of the pros and cons. I haven't told her yet, I'm waiting to bring her to the ultrasound when we find out what we're having in two weeks (I'll be 16 weeks then). However I have been dropping he idea to her about having a brother or sister and she has been really excited about the idea and has been asking tons of questions about it. Any advise or opinions would be appreciated.