Start by controlling wake up time. Her "natural" wake up time, according to what you've described in your last post, is 7 or 7.30 am. The fact she went back to sleep is due to the late night. It's confusing her body clock to go back to sleep at 7.30am.
Get her up and dressed, whatever, start the day at 7 or 7.30 ish. The ONLY time you break the "never wake a sleeping baby" rule is when you are controlling the wake up time to protect the next nap or bed time.
Give her lots of light and do her morning feed out of her room. Start winding her down about 90 mins after wake up, even in the bedroom if you wish, then back in bed 2 hours after wake up.
Morning sleep shouldn't be longer than 2 hours. Awake again for about another 2 hours, then same routine as morning, settle after 90 mins, back in bed after about two hours.
Play the afternoon nap by ear, but it shouldn't happen after 4pm and shouldn't be longer than 45 mins to one hour max. If no late pm sleep, then try having her ready for bed by 6 so there's time to settle her down (I don't mean she should be asleep by 6, but no being downstairs or in the bath after that because it's too stimulating). If she does have a late pm nap, then aim to be ready for bed by 7ish.
I know it all sounds a bit "by the clock" but it sounds to me like her body clock is a confused. The way to fix it, is to control the wake up times and nap times. It won't happen overnight, but it should settle in a few days, even if it gets worse first.
Do buy that book I recommended. I've given it to loads of people and always have good reports.
Your baby doesn't sound like one of those babies who just sleeps when they need to, (I'm told they exist; I've never met one) so you need to be her timekeeper. Once she knows what to expect, it should get easier.
Do remember things such as; low lighting in the bedroom. Closing curtains and turning lights off or down helps babies to understand that it's sleep time. Keep everything calm and quiet.
Lots of people would disagree with me, but when I tried this with DD2, she cried for over an hour the first night, but it was about 20 minutes the second night and only 5 the third night. I only tried it in desperation because she was so, so unhappy with me holding her at bedtime. She could NOT switch off. She still finds it hard at 2.5 yrs. Talks to herself for ages after I leave the room. However, with DS1 (third baby) I was able to shush him gently after his feed and graduated from putting him down asleep, to putting him down almost asleep, to putting him down awake. It helps that he sucks his finger for comfort. The final "bit" is different for everyone, but I promise you that that final part where they go in the cot, will always be easier if babies are well rested and know what to expect.
Good luck!