Hospice is coming out tonight to talk to mom about care. Any helpful advice would be appreciated.

Ask all the questions you would ask of ANY Health Care provider.
I am sure they will go over all the "rules" and the "do's and don'ts. An important one is who to call in an emergency. (Be sure to ask though what to do if in an emergency there is no rapid response from Hospice. How long do you have to wait for a call back or a visit from a Nurse on Call.)
Ask what Team you will be assigned to. (Just for your own information)
Each Team has Nurses, CNA's, Social Workers, Chaplains and Volunteers. They all work together to make sure that your mom will get the best care and you will be supported as well.
Ask if they use an APP that will allow you to communicate and keep informed as to what is going on. (The Hospice that I used for my Husband used Tap Cloud, great way for your mom to communicate with her team as well.)

I am sure by the time the meeting is over you will be more comfortable and just know that if you have any questions ever day or night you can contact your Hospice.

Lot's of open and honest conversations!
https://hospicecare.com/what-we-do/publications/getting-started/introduction/

This site has a film to watch: This shows why people are attracted to this job.
https://www.chifranciscan.org/health-care-services/hospice-and-palliative-care/hospice-care.html?&s_kwcid=AL!12180!3!256977431984!p!!g!!hospice!933469834!47657814438&ef_id=Cj0KCQiAjc2QBhDgARIsAMc3SqTNj_NpQt6BzJfUMi-_ET4kz3_qzzcw4EjVlSD5KbKbY3AAFZ-ebsYaAiwMEALw_wcB:G:s&gclid=Cj0KCQiAjc2QBhDgARIsAMc3SqTNj_NpQt6BzJfUMi-_ET4kz3_qzzcw4EjVlSD5KbKbY3AAFZ-ebsYaAiwMEALw_wcB

When my mother was placed in hospice last year, it was like she 'knew' what it was but didn't want to 'realize' what it was. I think she really thought there was a chance that she would get better (which, I know, has happened but rarely). Even up to the week prior to her passing, she kept talking about 'hoping to go back to her place'. But then she would be sharing with me what she wanted done with all her things when she passed.

I guess it was a blessing - she was in hospice for about 1 month before passing. But I had a friend whose father was in hospice for 26 months! So one never knows how long one has. Make sure that all the paperwork is in order as well - wills, etc etc. Unless you or someone else is already the POA, also would suggest that you get a doctors letter stating to the effect that your mother is in hospice and unable to make her own decisions. This would be important in handling her finances.

It will be up to you to ask the 'important' questions (and keep notes) -what is all involved; who will be the people visiting your mother (their names and contact info); frequency of visits; emergency contacts; who to contact if you have questions or concerns. Your mother might now know what or how to ask.

When my FIL was passing from pancreatic cancer the hospice nurses were just amazing: so sensitive to all of us in our sorrow and knew how to interpret his breathing patterns so they could tell us with uncanny accuracy how near he was to actually passing, even a 5-minute warning that his departure was imminent, and it was almost exactly 5 minutes. Bless them!

Hospice and all it entails will be explained in such a way to your mom that it more than likely will sound appealing to her, as they will supply all necessary equipment, like oxygen, hospital bed etc. all needed medications and supplies all covered 100% under moms Medicare. They will have a nurse to come check on her once a week to start, and aides to come bathe her at least twice a week, access to a chaplain, and a social worker. Their intent is truly to keep her comfortable and pain free until the Good Lord takes her home.
My husband was under hospice care for the last 22 months of his life, so just because she takes them up on her care, doesn't mean that her death is right around the corner.
I wish you and your mom the very best.