An ‘Installation allowance’ is a one-time payment paid to new employees of EU institutions that have had to change their place of residence. If the official is entitled to the household allowance (has a spouse or/and dependents), he/she will receive two months’ basic salaries. In all other cases the Installation allowance is equal to one basic salary.
Read the full article.
I confirm what X says. You’re entitled until she turns 27.