I personally decided to have a second child when "I" felt that I was ready. My oldest daughter was 3 and 3/4 years old when I gave birth to my little one (in 2004). I don't believe in any "rules" of how far apart they should or shouldn't be. I didn't have children so that they could be friends or have a playmate. Of course I want them to get along and like each other though. Which isn't always the case. Everyone has very different views on this subject. Other people will say not to have them any further than 1 or 2 years. It just comes down to you and your husband. What your gut feelings are. My husband and his brother are 2 years apart and they have never gotten along. My sister and I are 8 years apart. We are really good friends today. Every child is different. They each have their own personality. Anyway, like you said-
Your daughter is almost 3. If you were to have another baby they would have to be 4 years apart. Would you not have another baby just for that reason? I'm sure the answer is no. It's what nature has given you. Be thankful and enjoy the one on one time you have had and will have with her. Please don't be worried or have any apprehension on this subject.