I think my 18 month thinks she doesnt need her afternoon nap ( i know i do!)

I put her down at 1-2pm with a bottle, she has her bottle and keeps climbing down. i put her in, she climbs back out.

at the end i give up after bout an hour or of trying.

by 7pm she is dead tired.

Their bed time is 8.30 - 9pm

What do i do. she wont sleep at nights without her sister being in bed (they share a room), i cant convince my 3.5 to fake sleeping as she starts crying.

Im out of ideas and patience