I home educate my only at the moment, though just for the last couple of years - he was at school till then.
There's no reason why HE has to be an isolating experience, though I think with an only you maybe need to put more thought into where she will get the chances to mix with children in ways that will let her learn about getting on with people you don't agree with, dealing with different personalities, teamwork, etc.
But you can get all of that with any group of children you see fairly regularly - brownies, Sunday school, home education groups, activity groups etc.
What age is she now? You can often start going along to local HE groups before schoolage -that way you can start finding out what is happening locally, how active the groups are, whether they seem to suit you both etc.
There's a thread in the HE section about finding other HE families locally, and that's often the advice for people who are thinking about it - get in touch with those who are alreadt doing it!