"Allow her to retire comfortably"

The debatable part is if they meant immediately retire. Which 5 figures will not let you do. But will it allow her to retire eventually comfortably?

10 year US bond is 4.2%

Let's say she is 30.

Retirement age is 67. So 37 years until retirement.

6,000€ ×5 is ~$35,000

$35,000 at 4.2% interest for 37 years is $160,388.66 (This isn't taking into consideration reinvesting the 4.2% interest after 10 years, but also ignoring things like taxes)

But getting $160k when you retire would allow a lot of people to retire comfortably.