Socialization will always come up when you homeschool, whether you have five kids or one, whether it's a comment from Grandma, the store clerk, or those unsure voices in your head (am I doing enough??). The problems can really arise when you're homeschooling an only child though. It's true they don't have the benefit of a sibling that is always around, whether they're playing nicely or arguing.
Being a homeschool mother of an only child I'm often faced with doubts and wonders in my own mind if I am doing enough for our son. He goes to karate practice once a week, has three wonderful public school cousins he plays with weekly and goes on outings with, and he has a good neighborhood public school friend he plays with almost every day for a few hours after she gets out of school. But is that enough? Public school kids are around other kids for 40 hours a week! We don't come close to matching that... and that is perfectly fine with us!
Although I have to admit, it took me a long time to come to terms with that. It is daunting to think of how much time public school kids are around other kids. But is it all roses? Probably not. In between being quiet in the hall (and sometimes at lunch), being even more quiet in class (how many public school kids come home with a "bad color" each day because they were talking in class?), bullies, to shorter and shorter recess times, and to being exposed to kids who are only within their specific age range (no where else in life will large groups of people be segregated based solely on age).
Most kids, no matter where they go to school, usually have "best friends" that they met somewhere outside of school anyways. Not even half of my childhood best friends were met at school and none of the ones I met outside of school were ever in the same grade as me, we were always one or two grades apart.
So what can you do to help your homeschooled child get around more kids and make some friends?
To start, it is very easy to replicate recess time in a homeschool enviroment because you are free to go to the park whenever you want. You can go during school hours and probably not run into many kids, but you can also go shortly after school lets out or on the weekends and have plenty of kids for you child to play with. And even better, you don't have to be done in 15 minutes if you don't want to be!
Local libraries often have story reading times (where singing and dancing games are usually incorporated) for free for younger children, tween game nights, teen anime and discussion groups. The events your library holds regularly are probably bountiful even if you don't live in a large city. (Our library is small and does all those mentioned above plus more.)
Extracurricular activities are of course another option (and usually a fun one at that). Karate, dance, gymnastics, boy/girl scouts, the local YMCA, little league, or any other team sport are just some of the great options that are offered in most any city in the U.S. that your child will have great opportunities to meet other children and form relationships (and also to work in a group setting).
Even a trip to close by but low cost places can help your child find friends. A trip to the beach, lake, children's museum (they sometimes have free or very low cost days once in awhile too), or even the local McDonald's play area all are opportunities to interact with other kids and possibly make a new friend.
So even if you don't have many cousins for your child, neighborhood kids around, money (remember the libraries events will be free and the YMCA has a low cost option for families that need it), or a local homeschool group, there are alot of opportunities for socializing your homeschooled child.
But the bottom line is, is your child happy? Even with everything my son was doing I was paranoid it wasn't enough. But I realized a couple weeks ago to just relax when I was worried and blurted out my thoughts: "He (my son) doesn't have enough friends". Well, let me tell you, he heard me and replied in an insulted kind of way: "Yes I do have friends!" and proudly proceeded to name off all of his cousins, his uncles and aunts, mom and dad, his neighborhood friend (who is three years older and a girl), and the kids at karate that he hasn't even played with outside of karate. He thinks he has alot of friends and he's perfectly content just the way it is. And he's an only child homeschooler.