My friend constantly criticises me – should I confront her?

I am at a point where I make myself as small as possible in her company to slip under the radar

I am lucky enough (aged 55) to be in a small and fabulous friendship group of me (single) and three other women, all happily married. Recently one of the ‘girls’ has been singling me out for criticism and making unkind comments: Criticising my parenting methods or berating me for my eating and drinking habits (I like to eat/drink in moderation – she does not). 
A recent trip abroad was somewhat soured by her insisting I ordered pizza when I wanted a salad, as well as filling up my glass repeatedly with wine even though I declined. I feel bullied and I am at a point where I make myself as small as possible in her company to slip under the radar. She is essentially a kind person but do I call her out or do I suck it up for the benefit of the friendship group?
– Cowed
We want to reassure that every single person we know has been through a situation like this. If we were betting women, we would put money on the fact that almost every person reading this column – sitting next to you on the train on Monday morning; sweating on that treadmill at the gym – has experienced a group dynamic shifting. Tension among friends where there was once none.
An unexpected fault line where, before, there was only wisdom, wine and laughter. This has happened to people at school, at university… at every conceivable point in life. You can’t imagine it happening when you are in the first friendship group flush. And then, suddenly, the corrosion is all you can see.
There are myriad reasons why these fissures appear. Changing circumstances can become an issue whether it’s money, sobriety or relationship status. You are single and any otherness can encourage those with a subconscious tendency towards bullying (an ugly word, we know, but that’s how it probably feels, dear Cowed). 
We have a theory, old-fashioned though it may seem, that, as a single person, you are more vulnerable to be given a hard time because you are perceived as less protected. No partner is going to pop up and say, “Do you know what? Don’t talk to my person like that”. You’re not going to go home and say ‘This happened and it made me feel weird’, because there’s no one to say it to.
You say that all the others are happily married. How do you know? Anything could be going on in their marriages, families, professional lives. We never have the full picture. And people – we are no exceptions – will often act out on their own unhappiness. Anything to externalise it. Anything to spread a bit of pain.
She may not know she is doing it, but she is seeking you out for a reason and it could be that something in you is triggering her. Perhaps your singleness reflects a lack of freedom for her. Perhaps she wants you to eat and drink more because she’s uncomfortable with your self-regulation. Perhaps she thinks you need managing, because you are the single one. 
Perhaps she is a manager by nature; her children have left; she needs to run someone and she has decided that person is you. Perhaps something about the choices you are making is offending her or making her feel self-conscious about the choices she is making. Who knows? We always think friendship dynamics are fixed, but they continue to change. Everything and everyone changes – particularly at this stage in life when people are often howling, ‘What am I here for?’ or entering a power surge.
So, if you’re feeling brave enough, you could say something like: “I sense that something is not right between us. It feels like it’s changed. I’m so fond of you and think of you so highly that I’d really like to understand”. And if she says, ‘What do you mean?’ you could say: “I just feel that you’re not comfortable with the way that I do things. And I feel self-conscious about it.” Whatever you do, don’t say, “And the other girls agree.” 
You say, in your longer letter, that the other women in your group have noticed, and while that is consolation and even validation that you are not being paranoid, we would say AVOID the tendency to rope others into your argument. That is a modus operandi best grown out of. And she may well deliver a point of view that highlights your part in this strangeness. Be prepared for that.
Some awkwardness lies ahead. But awkwardness won’t kill you. You have been sitting there, taking the hits and merely simmering but, as your resentment builds, you risk an explosion that could do irreparable damage to the friendship. Or, you might just start avoiding the group gatherings, making excuse after excuse, and you will have lost that connection anyway. It would be brave to give yourselves the chance to untangle whatever knot this is. 
You don’t need to martyr yourself on the altar of this friendship group, but you might need to sacrifice a little bit of ease in order to uncover what is really going on. The anticipation of a confrontation will feel scary, but important friendships always suffer periods of dis-ease. That is part of what makes them important.