Michael Strahan's Daughter Isabella Enjoys Vacation R&R Amid Tumor Battle

Michael Strahan's daughter Isabella is finally kicking back for a much-needed pool day ... after wrapping up her last radiation treatment to tackle her brain cancer.

The 19-year-old posed away with her twin sister Sophia in a series of bikini-clad IG snaps Monday from their sunny vacation ... captioning it, "In good company."

Isabella also enjoyed some R&R at the beach ... smiling wide as she made the most of the break before starting chemotherapy next month.

She said she was excited to be done with radiation during a candid YouTube video last week ... nearly 3 months after doctors found a malignant brain tumor.

She explained on 'GMA' earlier this month her cancer is known as medulloblastoma -- noting docs discovered a tumor as big as a golf ball lodged toward the base of her skull.

Upon the discovery, Isabella underwent emergency surgery at Cedars-Sinai in L.A. ... where she's attending college at USC. The procedure to remove the mass appears to have been a success.

Her dad dropped everything in NYC at the time ... booking a flight to the West Coast to be by his daughter's side -- which explained why Michael had been off the air so much back in the fall.