Question about my cat

Is it normal for Maine Coons to Trill?? Both my cats do it. my Male, Charlemagne trills & chirps but he does "eeeao" alot lol my female, Alaise I have heard mew only once and it was a quiet one at that; she is the triller, chirper, and she makes trill like hightoned noises but she doesn't mew.
My Cats are half Maine Coon, and half American Shorthair, my neighbors sister owns their parents; the father; is a reg. purebred. their mother is an American Short Haired Tabby from what I am told.
Also; my male is large (not surprising) but Alaise, his sister is so itty bitty! I would have thought she would be growing bigger but perhaps she takes after her mother? (don't know)



That is Alaise above
And Below is Charlemagne, and in both pictures you can see my leg (if that helps with any comparison)
They were born July 16, 2012.

Yes I've heard MCs making chirpy trilling noises. It's funny when you see the really big male MCs and they have this chirpy little voice. There can be a major size difference between male and female MCs, incl. brothers and sisters born in the same litter. Sometimes the boys look about twice the size of their sister. Plus when you're talking mixes, there's genetic influence from both parents. and as you said she may take more after her mother. Those are some very striking cats. Looks like they do have MC-ish muzzles and ears. & the coats -- At first I thought, that is a very cool-toned Brown Classic Tabby ... then I thought wait that looks like Silver Classic Tabby. but just not with the same contrast as in some of the pedigreed cats that were selectively bred for that( like google Black Silver Classic Tabby American Shorthair. you can see it is very high contrast). For them to be silver tabbies, one of the parents would have to be silver or smoke. What color/ pattern are the parents? For the father it will say it on the registration, if you're able to ask.When you say the mother is American Shorthair , do you mean the pedigreed breed American Shorthair, or do you mean a random-bred "domestic shorthair" who happens to be from America? ( because it would make a difference whether the cat was selectively bred for color.) Anyway, thanks for sharing!

That second photo is just priceless! It's like the cat's going, "Yeah, yeah, I'm gorgeous; now put away the camera and give me the attention I deserve, human slave!"

Hi! I am so sorry it's taken me this long to re find this forum! lol The Father was a Red Maine Coon and the mother I dont know; was told that she was "American Short Hair". 
I am including two pics of their father Simba and some Recent pics of Charlemagne and Alaise.



Simba (Above)
-----
And Charlie (Charlemagne)




And Alaise (Below)




And here is one of both of them together (Alaise is In the Window and Charlie has his head popped up)