"She has to shower today."
Translation:Ella tiene que ducharse hoy.
Mark, you will use que after a form of the verb tener to talk about obligations:
- tener que hacer algo - to have to do something
- Tengo que leer este libro. - I have to read this book.
Don't try to make prepositions and other small words match. Remember that English and Spanish are different languages.
As ProfesorAntonnio explained in a reply to a question by Nimalibu, you can either place the reflexive pronoun 'se' immediately before the beginning of the verb phrase or you can attach it to the end of duchar.
Ella tiene que ducharse hoy. -OR- Ella se tiene que duchar hoy.
"I don't want to shower today." --> "Yo no quiero ducharme hoy."
-OR- --> "Yo no me quiero duchar hoy."