It’s not her property, though, you should only have to stop if the owner tells you to.
That’s competently wrong.
She paid the landlord and in return she was given the right to control access to the property. That’s what renting is.
The inside maybe, not somewhere the public is allowed to access, such as the path to the front door to deliver something.
There, too. A tenant has the same right to exclude people from his leasehold that the owner would, absent contrary language in the lease.
Isn’t the lien aspect accurate?
Also, apparently the landlord never hired OP in the first place, and, if he did, he isn’t getting paid anyway. The landlord will be less pissed because he is getting fair warning and will know that he has a deadbeat tenant.
I’m curious in what financial world you live?
In America, that’s called ‘putting a lien’ on someone’s property.
If you ever decide to spring for a membership, this would make a great sig line.

You don’t have to be a member to have a sig line. See? I don’t remember what my sig is because I never use it, so I apologize in advance if it’s something offensive.
I live in an apartment building, with a shared hallway, lobby, elevator and so forth. So if I get a no-trespassing order against someone, does that mean they can’t walk down the hallway outside my apartment? What if they’re visiting a neighboring apartment? (Purely hypothetical of course.) What if they walk up to my apartment door and post a letter or notice on the door, or slip it under the door? Are they violating the no trespass order in doing so?
No, common areas are treated differently. If your apartment was a condo, the owner could not exclude people from common areas (though a court might issue a no-contact order prohibiting a non-resident from them if that person had threatened you or something). I am assuming that the property discussed in the OP is a “standard” single family home, since it has a yard.
I’m just exploring the possibilities here; what if the home in the OP had no yard, but the door opened directly at the sidewalk? Could the OP post a notice on the door without violating the order?
From what I’ve read, a contractor being able to take a lien against the landlord’s property is pretty unusual. It generally requires that the landlord made a crappy lease contract or does something to entice the tenant to have work done (like renting a space that obviously needs finishing or renovation). Note that neither of Peremensoe’s examples of getting a lien on a landlord’s property involve a simple private contractor doing work that the tenant wanted - both involve the landlord failing to follow laws about property maintenance. Here’s a doc from Florida and a more general one on the topic:
So, I think in most cases the lien threat is either BS or the landlord will believe it’s BS. Trying to get someone to help you with a threat is tricky enough, but if the person doesn’t believe the threat (whether justified or not) then you’re pretty much guaranteed to make them hostile to you. That’s why I recommended against trying to muscle the landlord into helping you, I can’t see it going very well for you.
I know if I was renting a property and someone came to me making threats about filing a lien because a renter didn’t pay up, I would be inclined to tell them that their company is no longer allowed on my property at all, and wait for them to go to court (if they even get that far). If it’s a small amount of money it won’t be worth the filing fees, and if it’s a large amount of money it’s worth fighting to keep it off my property. If I’ve had trouble with the tenant then I’m going to want to get rid of them regardless of this issue, and if not then I’m going to suspect that the contractor threatening me is shady or an outright scam artist.
Then help my ignorance here. In commercial real estate in Maryland it’s my understanding that people doing service work to a property can file a mechanics lien against the real estate if they do not get paid. The commercial leases we use recognize this fact and instruct the tenant they must correct or satisfy any such liens placed for work they ordered or they are in violation of the terms of the lease.
These liens (if successfully placed) attach to the real property and can impede the property owner’s ability to get a loan or sell the property if they are not removed.
Is this understanding incorrect?
Also, the majority of liens do NOT require a court judgement.