Age gaps

Growing up I had great relationships with my cousins, we were close in age and played all the time.

My sister is single and my bfs sister had her first young (he is now 10) and her youngest is 3. Me and my bf aren't at a point where we are ready for kids yet however, being the chronic over thinker I am, I'm scared by the time we are ready that our children will have large age gaps with their cousins and won't grow up having good relationships with them.

Are there large/small age gaps with your children and their cousins? Does it affect their relationships with them?