I think there are two ways to approach this really. The first and perhaps easier way is just to do EAS cycles beginning with whenever she wants to begin her day. Fussy evenings are very common for young babies so the want/need to get up later is very common. Often after 8-12 weeks things become more settled and it's fairly easy to move bedtime gradually back to a more reasonable hour, and therefore start your day earlier. However if you'd prefer to get back to a more normal 7-7 day, perhaps aim for a wake-up 'window' of say 6.30-7.30am. If she wants to go straight back to sleep at 6.30am then let her but then maybe wake her at 7.30am to start the day? What do you think?