Blimey. I don't know why you think it's such a mortal sin that she lied that you are all bending over backwards to convince me that she did not. You don't even know her.
I'm not saying she was a mass murderer, I am saying she lied, which she did, on two censuses
It is not a case of trying to convince you she did not lie. You seem determined to prove she lied, and it's quite possible she did, but in order to do so you need to look at all the facts.
Looking at the 1901 census first, the only source is the Enumerators book, there is no indication as to who supplied the information nor what was supplied so it is difficult to prove beyond doubt that she lied. Also, the 1901 census asked the marital status, if she answered married and her first husband was still alive then she didn't lie. If she called herself Mary Bloggs and that was the name she used then that's not a lie so unless there is something else then the 1901 census information is not a lie.
Out of curiosity when did she marry her first husband, if it was 1897-1898 then one thing to be aware of is that the question on the 1911 census seems to have caused some confusion, whilst the years married and number of children related to the womans current marriage, comments on various forums suggest that quite a few people seemed to have misunderstood the question and included all marriages and in some cases the male answered the question.
Andy