Unless you are in an extreme hurry due to the person with the uterus being close to being too old to be pregnant I would say just wait a little. I had my kids at 30 and 34 and I had no wish for number two until my first was about 2.5. By that I mean NO desire what so ever to the point of almost avoiding sex because an accident could happen. Then something changed and when our oldest was just over 3 we decided to have a go at making a baby and we got pregnant right away that first month. I was surprised because you hear all about fertility dropping after 30 but I was in fine shape that month when it comes to fertility as it seems. I was still very worried about parenting two kids and I did go to a psychologist during my pregnancy to help me handle the things that had made it hard for me to consider having another baby and then my shock at getting pregnant so easily and finally handling my problem during both pregnancies, that I feel like crap every single minute I am pregnant mentally. It is like 9.5 months of PMS without stop. Both my pregnancies were long too, 42+4 and 41+6 so I even got an extra "sentence". Once my second was born most things were so much better than I ever imagined and two was easier which I thought was a complete lie when a lot people told me that while pregnant.
My kids love each other and they play together, the older helps with teaching the younger things, the older makes breakfast for them sometimes during the weekends (OK, it is just fruit, crackers and milk but she still does it), the younger will hug the older and shriek of joy when the older comes in after being outside to play or with a friend. They fight and they hit each other but mostly they are friends. When my oldest told my youngest "You are the best baby brother ever and I love you!" and I could hear that she meant it with every fiber of her being I was a proud parent. For us having another one was a great decision and now it feels weird that we even thought about not having two. I know not every sibling pair will be the same but for us the fears didn't come to life. I can even imagine having three kids but that will likely not happen but the idea doesn't feel crazy.