I completely understand wanting to start with healthy habits to avoid unnecessary issues later - more so with a toddler in the mix but these are early days and I do think it is fine to be a little lax right now. As long as you follow the basics - separating Eating and sleeping with some A time like changing her diaper or looking out of the window, keep A times short( we did only 1 hour at that point but Tracy advises 1.5) and avoiding overstimulation, you should be fine. Do you follow the 4 S wind down? With my DD, I would hold till drowsy and then PD and leave the room. Shushing in the crib just agitated her as she wanted to be in my arms. Same thing if she saw me in the room.
Short naps are also part & parcel of these first few months. Have you tried being in the room *before* she wakes up and patting her back to sleep before she fully wakes? White noise also works wonders to lengthen naps