LSL WA

we have an employee who has been with us for 7 years today.  I know if she left she'd be paid pro-rata for LSL.  You have to be with the company for 10 years before you can take your LSL, but when does the accrual start?  At 7 years or 10 years ?  She is full time, 38 hours PW and Salary.  TIA :-)