Lina Lamont and Billie Dawn: Sisters From A Different Mister?

Sometimes things are so obvious you just can't help but wonder: Were Lina Lamont ("Singin' in the Rain") and Billie Dawn ("Born Yesterday") related?

We don't know anything about the parentage of Miss Lamont and only know that Billie's dad worked for the gas company.  Let's take a look at a few undeniable truths.

First: obvious physical and seductive resemblance. You see it, right? Sisters? Mother and daughter?

Second: the even more obvious vocal resemblance. I mean, really - can there be any doubt that these two have a memorable -shall we say - tone? 

Sorry for any ear bleeding here,

Third: the shared impression that both were not bright when, in fact, they were smart cookies. While Billie mastered her civics and brought down a millionaire crook, Lina knew all the ABCs of her studio contract.

Fourth: while we know that Billie's first name is really Emma, we don't know her given last name. And it's a pretty good bet that Lina Lamont is not the lady's real name. It has proved impossible to obtain actual birth certificates for each gal and back then there were no DNA tests.

So, I'm going to posit, without any proof, of course, that somehow these 2 are related. Billie would have to be the kid sister, of course or...could it be that somewhere, somehow, Lina had an affair with the gas man?

I leave it to you to ponder.