How do I know if my supply is ok?

[PaulinePetrovaPosey]

DD is 7 months and EBF. No issues at all with feeding since I got passed the first few weeks.

She's taken to solid food really well and is now on 3 good meals a day, and she's also mostly sleeping through so I'm not feeding at night very often.

I know I'm lucky in all of this! But I'm starting to worry that my supply is dipping. In the late afternoons (a bit before I generally give her dinner) she is getting really crabby and - unusually for her - doesn't seem to stay latched on when I try my usual trick of feeding her to stop the whinging.

I'm wondering if this is because my supply has dropped and so she's hungry but not getting anything - any ideas on how I would find this out or fix it?

Is she wanting food and getting too irritable? Would an earlier dinner help?

If she's healthy and wee and poo ok I imagine it's probably fine. Although I don't really know what I'm talking about DS would only breastfeed until he was 18 months

If she's on three good meals your supply should be dipping.
It's only a problem because she's crabby for reasons that probably aren't to do with wanting milk and you're trying to bf to fix that (which would obviously be fine if it worked, but it isnt). Some babies like to feed for comfort, some don't, some are fickle.
I reckon if you either change a nap time or meal time or milk time, it will help with the crabbyness so you're not trying to feed her when she doesn't to. Personally I found 4hours between meals each followed by milk then nap worked for us at that age but everyone is different.
I'm not saying she doesn't need the milk by the way, just not right then.

Weaning is the gradual increase of solids and decrease of milk. Your body will adjust to baby's needs and baby will need less.

The late afternoon grizzle is likely baby saying they are ready for their tea so I'd move it earlier or introduce an afternoon snack.