Welcome to toddlerhood. It's a bit of a shock when your largely compliant and sweet baby turns into a toddler!
My son just turned 23 months too. I have a four year old DD too.
- at this age ("young toddlerhood") they can't really be obedient as such. That comes later at around 3. I remember tearing myself in pieces as my DD would not do as she was told at 2. Turned out she was just not old enough yet - under around 3 they are just COMPELLED to keep doing (or not doing) whatever the thing is. It's developmental and while its alarming for us, if you remember that, it helps! They are supposed to be like this, and they won't be like this forever!
- pick your battles, in relation to everything but especially re food. I can't emphasise this enough! If you get involved in a big stand-off in relation to every little thing, you are going to burn out in about 2 weeks and no way will you last the full course of toddlerhood! Eg food - your example about the grapes. With an older child, you can insist that they at least try food x, y, and z and then they can have pudding, because older children understand rewards and have a concept of time. You just can't do that with a 23 month old. If I were you I would just let her have what she wants, and later in the meal, once that moment has passed and she has forgotten she was making an issue about it, offer something else that she likes. If she is really hungry then offer her toast at bedtime or something. My son normally eats fairly well. But sometimes he takes two mouthfuls and then shoves it away or starts messing around. If that happens I don't try and get him to eat (well I have a little go but normally he is very clear about it!) So instead I just give him a mound of natural yoghurt and offer an oat bar as well.
- make "yes" your default setting. By this I mean, every time she asks for something, e.g. to be carried, or wants to get out all your pots and pans or whatever else totally inconvenient thing it is, I would say "yes" unless it's (1) dangerous to her or others (2) antisocial or (3) you REALLY haven't got the time. It gives them the sense of control they need and helps them be less stroppy and tantrummy. A toddler who feels that they have influence in the world is a less shouty toddler. Great for this is letting them get involved in grown up stuff, like cooking or loading the washing machine. My son is chuffed to bits if I say we are going to cook "together" - I normally give him some totally pointless task like taking the beans out of the packet and putting them in a pan. But he thinks he is playing with the big boys!
Obviously there are dangers with older children (3 or 4 year olds) that if you say yes all the time you end up spoiling them, so I think the trick is to gradually, as your child gets older and more able to defer gratification and fit in with others, have a very sensitive hand on the rein and start to expect more of them and start telling them that no, they can't always do it their way or have what they want. But at 23 months they are still very very little. You will notice as your daughter moves closer to 3 that you can start expecting more of her. But for now, say "yes" unless there is a really good reason not to!
Good luck! It does get better - my daughter is 4 and three months. She has just read me a story, put all her washing away in drawers and her brother's too, told me she likes my new haircut and that I am the best mum in the world!
I sing to myself during one! I ignored, ignored, ignored. Walked away and left ds too it would step over him if he lay in front of me. In shops I'd either walk away or pick him up (firemans lift) and leave if dh was with me or simply carry on regardless.
After tantrum when behaviour is good give loads of attention and praise.
I find mentally rating the tantrum like the Strictly judging panel takes some of the sting out of it - can develop all kinds of elaborate mental scoring systems for style, creativity and wrathfulness... just brings you back to how irrational and absurd the reasons for some of the tantrums are and stops you getting caught up in it all snowballing into a lump of mutual stress.
OP whatever you decide, you have to be consistent, deal with things in a very similar way when at home or when out and about. As you say, it is all about control and satisfying what she wants. DCs aren't going to behave well in public unless they are used to behaving well at home and in general.
DD probably has tantrums when she's tired or hungry so be prepared to use her buggy or give snacks you've kept in reserve. Little ones don't always handle decision making well, if she's already stroppy don't give her choices, just tell her what's happening.
Around her age I suspect it is very normal to have a funny phase about eating. Sometimes it's purely for attention seeking or as you say, a control issue. That said, could she be about to get some new teeth through? or coming down with a cold?
If I were you, I'd just take a deep breath and try giving her very simple food. Do not show you're wound up if she rejects it. You could try offering her the same food half an hour later. As long as she is eating something and drinking milk she will be fine, she won't starve herself.
If you stay in the room but busy yourself doing something, she might actually relent as she won't get attention from you.
In any event, when she tantrums, get down to her level, make eye contact, talk to her to try to find out whats wrong and persuade her to calm down. Reasoning with a toddler is like herding cats but on some days she may listen. Try and preempt the battles, second guess the triggers.
When she's older you can set boundaries and teach her about consequences, ("If you do this then you will miss out on that").
Toddlers have an uncanny knack for knowing when you're stressed or late or embarrassed. They will push you to the giddy limit. If she kicks off in public, just remove her from the situation, if she is not listening to you and really playing up. Pick her up and carry her out of public gaze if possible, but be prepared to challenge her behaviour in public. For every tut or disapproving look there'll be three thinking good for you, they're all the same at that age, nicely handled!
My 23 month old daughter is very intelligent and she has started only wanting her own way, and being in control. For example, wants to be carried and if not throws herself on the floor - or - wont eat anything unless she's asked for it, so if she wants grapes for her dinner, she will only eat grapes. I will offer her other things then say 'unless you eat your dinner, no grapes' so she will eat nothing. This has resulted in waking in the night hungry. Her favourite word is No.
Any advice would be lovely? I feel like I'm struggling. She's been good as gold up until now - and I'm very encouraging when she is well behaved. However I'm not sure how to deal with the tantrums!