Only way you'll lay her now is by going balls out and charming her. Going to have to ask her on a proper date and grind it out with persistence. She knows your hand now so theres no way around it ! your just going to have to bite the bullet and take her on dates until she wants to put out

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Personally this is what i would do in your situation...
Text her this -
Hey hows things ? Sorry i havent text you in a while ! Hecticness busy lad these last few days. I had an ideaa btw and you might enjoy it ! x
If she responds positively asking what you have been upto etc there is still a hope.
This way your catching her attention by telling her you have an idea but yet your apologising not for cancelling on her but she will feel some sort of relief from you saying sorry.
When she responds asking what your idea is. DO NOT TELL HER what it is yet ! play with her.... 'Well if i tell you you have to agree too it !' She will more than likely reply with i need to know what it is first.
Then just refuse to tell her ! just say well I KNOW YOU WOULD LOVE IT BUT IF YOU WONT AGREEEEE THE FINE !!! lol
She will agree ! Next move dont tell her after shes agree'd! tell her she'll get something delivered which will tell her what it is and when! Send her flowers with the time date and where to meet you ! Low budget rose if you fancy !
She will be flattered and her mind will be going crazy with what it is. Take her to your Art show thing and dinner ESCALATE LIKE CRAZY IN THE ART SHOW ! Walk behind her hold her hips ! Say come see this, put your hand out for her too take it etc ! go for drinks after and kiss close possibly lead to full close.
This is just basic charming but has mystery to it ! Its the only way you'll take her on the emotional roller coaster she wants. I've done it and it works if you know how to play it.