There always 'a number of studies' to try and 'prove' single women are happier than married women. I wonder why that is?
Neither myself or anyone I have ever known has EVER been asked or interviewed, or taken part in any 'study' about who is 'happier.'
Those 'figures' mean nothing. I was single until I was 24, and have been married for over 20 years now, and I bloody love it. Being married is way preferable to being single ANY time, for me, and many women I know. Some single women I know are pretty miserable, not well off, and struggling financially all the time, and working all the hours God sends to keep a roof over their head. The married women I know work part time, or are stay-at-home-mums, and have a lovely comfortable life.
Anecdata just like yours. I am sure lots of single women are chuffed to ribbons to be on their own. Many are not. Why do you think so many do so much online dating? Many single women are secretly hoping they will meet 'the one' some day. Very few people want to be single permanently. SOME are very content with it. SOME are not.
I reiterate. It's bollocks that single women are happier than married women. There's happy and unhappy in both. And it's always single women who spout this 'single women are sooo much happier than married women' line too.
Anyone would think they are trying to convince themselves. 
You do you. Stay single by all means. I will stay married. 
Not being funny, but I do get so fucked off with the 'all married women are weak, downtrodden slaves who hate their lives, and all single women are strong, happy and free, and loving life' mantra. It pisses me off. And it's not true.