XP: Growth spurt/establishing routine

mejane123

I go back to work in two and a half weeks from maternity leave (sad face), and DD will be a little over 3 months old and going to the IL's every day.  I get up at 5 to get ready and then I'll leave the house with her at about 6:15. Right now, she wakes up anywhere between 7 and 8 for the day, with a feeding and a diaper change around 4.  But now, all of a sudden, she's sleeping til 9:30 a.m. most days and waking up for a feeding around 6.  

My two (three?) questions are, could this sudden change in sleep just be her 3 month spurt and likely won't continue (she'll be 3 mos next week)?  And, when did you start a regular wake up routine with your LOs? Should I maybe start now so she gets used to being fed and in the car at certain times, or do you think 3 months is too soon for that?  

In case you couldn't tell, I'm a FTM Thanks! 

ETA: We do already have a nighttime routine.  We go up to bed at 8 and put on her white noise, put her in her sleep onesie, swaddle her up, and she usually falls asleep between 9 and 10.