Move lunch to 11.30, before nap time not after. Try to give enough so a snack isn't needed and just offer a drink when waking. But if you feel snack time is necessary, make it after the nap night before.
Ensure toddler drinks well, hydration is important.
12pm is a good nap time given your daily timings. I would copy bedtime routine exactly, right down to changing into nightwear. Do a wash instead of bath, but keep nappy off time, teeth brush, new nappy, PJs, story etc.
Endure you have fully blacked out windows. I'd recommend blackout curtains plus blinds. Put the curtain pole up higher and plenty wider than the window - this stood light bleeding around the edge of the blinds.
Finally, develop some means of extra help that you give to help baby sleep in the cot at lunchtime. Her pressure to sleep will be less than at bedtime, so you may need to give extra help. At least initially
My children have a dummy. So I would give dummy, stand by the cot and do a little face tickling and shushing until asleep, while leaning into the cot. If toddler went to stand up, calmly lie back down and continue. Repeating this a million times over as needed.