Will find my friends track my girlfriends SIM card or iPhone?

My girlfriend is visiting from abroad next week and we're planning on staying at a hotel for one night while she is here to get some alone time. The only issue is that her parents are very protective and would track her via find my friends and see she is at the hotel and would likely cause issues. I have another iPhone which I'm planning to have her swap her SIM card out of her current phone and put it in my other phone. If she is logged into my iCloud account, will her parents still be able to track us even if we leave her original phone at home?

Yes they can still track her as it is not phone related but rather related to the account

Find my Friends/Find my iPhone uses the phone's GPS and Internet to track the device. The SIM card is irrelevant except for the fact that it is used for mobile data.
In other words, if she has Internet access (Wi-Fi or mobile data), she can be tracked.

Definitely not.

Her SIM in your iPhone connected to your iCloud account will not show on that app.

It does not track SIM cards. Just Apple devices linked to the owners iCloud account.

It also can't track Apple devices which are turned off; it can only show where the device was when last used.

It tracks the device, but only works when it's on and connected to a network. It will still work if she puts the iPhone on airplane mode but leaves it connected to a hot spot