I asked if it was worth telling her off because would she understand? The answer is no it seems.
You can't expect a 2 year old to understand the concept of ownership.
The world is simply full of bright, fascinating things, & a toddler's instinct is to touch & explore everything.
They don't really 'get' "yours" vs: "mine".
The best you can do is tackle it in the moment each time. Just a gentle - "no, that's mummy's darling, I'm going to put it away safe now" & a distraction is all you need. It will sink in over time - you can't expect her to understand a rule about "mummy's stuff" & "my stuff" yet.
When I say marking her territory I mean she literally has to touch everything that is not hers. I appreciate this is just toddlers
It is, & I appreciate you were having a frustrated moment.
It's ok to feel really pissed off about a 'ruined thing' - so long as you don't show that to the toddler - AND to realise that with inquisitive small people, shit happens.
I have also realised through this thread that it is my own fault as I have been known to let her play with lip balm which is essentially the same thing ( although colourless)
Again - even if you hadn't allowed the lip balm play, she'd be attracted to the lipstick anyway. Because it is something she sees mummy use, & she loves mummy & wants to copy her & be like her.
For her, that's not about "mummy's lipstick, mustn't touch". She's still too small to fully comprehend what ownership of possessions mean.
I have a rule with dogs about food.
Dogs steal food. Some can be trained out of it, some are less interested than others - but in the main, a dog will be opportunistic around unguarded food.
So the rule in my house is - GUARD YOUR FOOD.
If you walked off & left a sandwich - expect to lose it.
If you left something tempting on the countertop, don't bitch about it when it's gone in 3 seconds.
Because FROM THE DOG's PERSPECTIVE, he is not a thief.
He is simply acting exactly like a dog.
To him - YOU stopped owning that food as soon as you stopped actively resource guarding it.
To him, you are a fool who gave him an opportunity. Or a human who no longer wanted her food.
You can shout at him about it (don't try this round my gaff, you'll be out on your non-resource-guarding arse), but you'll only confuse & scare him. You plainly no longer wanted that food, or you would not have declared open season on your plate by leaving it unguarded.
It's a very HUMAN thing to want dogs to behave like humans, while failing to understand that yeah, you can train them that nicking food gets them a bad response form humans - but they still won't change their mindset around what constitutes ownership. Because they are not humans - they are dogs.
Does this longwinded analogy help you at all OP?
DD is too little to understand ownership, so YOUR responsibility is to resource guard until she does. And that will take it's own good time - don't force it, just focus on prevention rather than cure for a while.