Deaths of Clara and the newborn-

I just finished chapter nine -- was Jane poisoning Clara and the newborn? Peggoty at this point suspects no foul play, and a quick google search returns no info on that question. It's made clear though, prior to the deaths, that Jane has complete control of the keys pertaining to certain areas of the house (if not all) to which Peggoty no longer has access, and Dickens also mentions Jane serving their tea. I think there was also mention of a bit of paranoia on Jane's behalf leading to restless sleep as soon as she arrives at the house? Thanks in advance.

eta: There is more on this in chapter xiv . Enough to satisfy what I suspected for now, was afraid to examine further on the internet for fear of any other spoilers. Just glad I didn't have to wait till the end to find out :) Or not.