In the sense of being a weirdly inspirational, quirky and reality-bending individual... well, yes, she could be. As good an explanation as any!
I wonder if PL Travers ever saw Doctor Who? As she lived long enough to dislike the Disney version of Mary Poppins she might have done...
^ Good point! I have assumed that James Bond is also a Time Lord, but for other than TARDIS-possessing reasons.
I remember, as a kid, my sister trying to explain the Tardis to me. I said, "OH, so it's like Snoopy's doghouse!" So, yes, I can totally see how Snoopy is actually a Time Lord in disguise.
And I guess the cat next door that we never see other than a paw swiping at Snoopy is the Master or another disgruntled TimeLord? Sincerely, Bill