I usually get away with being a single woman in ministry, because I'm still young. However, I know many older women (as in mid to late 30s) in ministry, and the reaction they tend to get is as if its a taboo. It's heartbreaking, because women are often treated as if they're helpless if they're serving God yet still not married. Even women who have intentionally chosen to be single are looked at as if they're crazy. I just don't see what's wrong with that--if that's what God's leading them towards... fantastic! (Plus, I've seen quite a decline in the amount of folks who are totally sold out, Jesus loving men. If this trend continues, the church won't have much option than to have a bunch of single ladies leading ministry.)

When I was involved in college ministry, my college pastor made it a point to never bring up my "singleness" in conversation with me, which sounds goofy or avoiding, but it wasn't. Yes, he still did ministry-wide talks about dating, relationships, etc., but our one-on-one conversations never included the dreaded phrases like, "Are you seeing anyone right now?" or "I think you and 'blank' would be great together." When I was dating someone, I brought it up. It was never the highlight of our conversations though. He set the tone for the ministry, and other students followed suit. We had a healthy mix of single, dating, and married students who all hung out together.

what comes to mind?

not knowing the place of ministry: i think of dedication, i think of service, i think of sacrifice, i think of opportunities that they have that i no longer have in the same way as a married mother with two young children.

knowing the place of ministry greatly shapes my perception of ministry.
knowing a single woman who works for a mega-church, as opposed to one who is on staff with a para-church organization, as opposed to a service-based NPO....WHERE single women choose to be in ministry shapes a lot of how i think of them. unless i know them exceptionally well, the organization tends to be the lens through which i view the person.

this is true regardless of gender and marital status....for anyone in ministry.

if there is a deeper relationship present with a single woman who is in ministry....well, the relationship that we have trumps any other variables. again, i find this to be true for ALL of my close friends.

As a single woman in ministry, I think, well I think many different things depending on the day. The one thing I think of mostly is how definitive a description of someone becomes the more adjectives you add to their title. If I was described as "in ministry", you would think all kinds of things. Some things would be genderless. Somethings would be gender-specific. In fact, if you're honest you would unknowingly assign a gender to the things you were thinking.
So now we add "woman" to the "in ministry" and that list of things you were thinking before might take a turn. You might redefine the list you had from before, or maybe you don't. But I'm betting that your list alters quite a bit now.
Then you add the final description of "single" to "woman in ministry" and once again the list get's a bit more specific with even more assumptions.
And that makes me crazy. Because yes I'm a woman and I'm single, and I'll admit that affects how I do ministry, it has to. As much as being a husband affects someone, or being a mother, or being a star athlete or a math whiz, or even left-handed. All those adjectives affect who we are, but they don't define us.
So that's where I land. I am single, I am a woman, and I am in ministry. I trust that God in His awesome knowledge has made me all three at the same time for His glory. As much as it affects how I am each of these (and let's admit being in ministry affects how we function in our gender as we as in our marital status, and it should!), none of these define me wholly. I am all three and yet beyond all three.
This is all pretty rambling but it's what first comes to mind.