Paris hotel -- unaccompanied minor

While a minor can travel internationally they can not enter into a lodging contract.
I presume this is a liability issue. Most hotels in the US I've worked at, or known of, wouldnt let a minor check in on their own.

Fair enough. The question remains though -- what can she do? She's in the city for 60 hours regardless. Any suggestions would be appreciated!

you may try to book an AIRBNB for her, less restriction.
i doubt anyone would check her ID

Try http://www.artyparis.fr/. You could try e-mailing them to confirm but as recently as a year or so ago, the minimum age to stay there alone was 16. Will you or another person over 18 be joining her in Paris? If so, I bet that if you contact a hotel, between you and the staff, you could figure out something like putting the reservation in the "adult's" name but letting your daughter in until the adult arrives. By the way, who told you that it is illegal for a hostel or hotel to allow anyone under 18 to stay alone? I am not trying to be confrontational but I don't believe that is the law -- I believe someone told you that but I do not believe that he or she is correct. Take a look at fuaj.org at their FAQs at http://fuaj.org/F-A-Q and note the answer to FAQ 6 under the heading IMPORTANT.

If you child it traveling without you, you may want to research "medical treatment of minors without parental consent". When our children were on overnight school outings, we signed emergency medical treatment consent forms.

http://www.protection-of-minors.eu/en/cat1.php

French legislation provide different regulations according to the age
and power of judgement of the minor, particularly in criminal matters.
Minors are children under the age of 18 years (section 388 of the
Civil Code). Young persons are persons between 21 and 25 years.

There is a YMCA in Paris. Maybe try there?

One airline (Alaska Air):
https://www.alaskaair.com/content/travel-info/policies/children-traveling-internationally.aspx

Minors (under age 18) traveling internationally without one or both
parents may be required to present a letter of consent signed by
any/all non-traveling parents. Please visit the U.S. Department of
State website at http://travel.state.gov "This indicates a link to an
external site that may not meet accessibility guidelines." for
country-specific information.

Have you tried contacting university residences?

FWIW, that law/practice has been in place for a long time. When I was that age, I could not rent a hotel/hostel room either and I am nearly 44. Young kids travel all the time but most of them are above the age of 18 or are travelling with someone who is.

For other readers here is the translation of the item referenced by JHK - - "Take a look at fuaj.org at their FAQs at http://fuaj.org/F-A-Q and note the answer to FAQ 6 under the heading IMPORTANT."

IMPORTANT

No proof is required at the time of the application of online membership but on your arrival at the reception of the Youth hostel in which you are going to stay, we are likely to ask you for a proof: a piece of identification To justify your age or a family record book to prove your family situation. Minors aged 16 or 17 traveling alone must possess a parental authorization, a photocopy of the identity card of the parent guardian and their own identity card. We thank you for bringing these pieces during your stay.

I'd try Generator or St Christopher hostels.
Bring a letter stating that you have parental permission, as the previous poster mentioned.

Excellent advice. Thanks!