Hopefully not!! Sorry, no advice or words of wisdom. Our LO is just a couple of months younger than yours and she only sometimes has a lie in if she has a 'late night' (by lie-in, I mean until about 8am, instead of her usual 7.15am wake up). Once in her life she slept till 10am when we were travelling for a holiday. Luckily for us, she is not an early waker in general, although we still have NWs for cuddles (bless).
My SIL said her LO started to have 'proper' lie-ins and adjust her sleeping times more effectively when she turned about 4 or 4.5.
(hugs)