In Summertime, Marielle leads Clare to the hospital room she will be staying in, and gives a book to read about the cancer and a hospital gown. She tells Clare that first she will get a catheter inserted into her chest. She later checks up on Clare and asks her why she isn't in her gown yet, saying she has to change since it is hospital policy. Marielle later puts the catheter into Clare's chest.
In All I Wanna Do, she informs Clare of group therapy, which she happens to lead. She later gives Clare's form to fill out for her MRI.
In My Own Worst Enemy, Marielle announces to Clare that her chemo is done for the day and that her MRI results would be reviewed that afternoon. Clare asks her if that is bad, and Marielle responds that she doesn't know. She tells Clare she'll try to get any information about the results that she can. When Clare goes looking for Paula, she finds Marielle there, cleaning the room. Clare figures out that Paula died, and Marielle sympathizes with Clare, who has the same kind of cancer as Paula.