DD2 is 5.7 now. Hmm...
I do think that the meaning gets lost in longer sentences. I think she relies a lot on clues around her for meaning. For example, when we read her school books, she always, always scans the pictures on the page before attempting to read the sentences. I don't know if all children do that, possibly.
Her comprehension is ok if the subject is literal and familiar. If it is out of context, contains words she isn't familiar with, or is abstract she really struggles. She seems to get 'stuck' if she hears a word she doesn't know the meaning of, so instead of just glossing over it as DD3 would and picking up the meaning from the rest of the sentence, she sort of seems to be halted by it.
DD1's carer said that she's never heard a parent explain so much to their children as I do. I didn't know that isn't normal, because DD2 needs it all the time. I just instinctively do it, because without explanation, DD2 won't be able to pick out the meaning.
In terms of 'disordered' language, she has said these things spontaneously (forgive that I've just copied and pasted from another post...it's easiest):
""Solid means ice"
"I am so shopping tired and all that twisting and turning I'm boy oh boy oh tired" (we walked to a shop and back)
"Patch can have tuna because it's strong for him"
"After I finish breakfast could I please not have orange juice."
"I picked up some sticks that had two or three layers and I gived them to some friends that I could see who I can invite to my party if you say so."
"What is making all those pieces of noises?"
Today, she said 'carrots come from bunnies, I think' to my Mum. We had to say 'no, sweetheart, carrots grow in the ground and bunnies like to eat them.' She said 'really??'. It's like she had the concepts mixed up in her mind.
She gets really upset because she hears something, gets the wrong end of the stick. For example, we're getting hens from DD3's preschool, but they only hatched this week. Last week, we told the children we were going to get some hens but they needed to hatch first. DD3 said 'are they here, now?' We explained again, that they were still in the eggs right now. She burst into tears because she thought that we should have them by now and that someone would cook them for breakfast. She's nearly 6 
Her reading comprehension is not good, I think. We read 'strawberry jam' and when I asked her what 'jam' is, she said 'it's a glass jar.' She doesn't pick up on the plot of stories unless it's read back to her and you point out key features.
I got the shock of my life when I read one of DD2's school books to DD3. It was about 'too late harry'. It got to a point where Harry had been asked if he wanted to help make a cake and he said 'I'll just go and get my apron...' DD3 said 'but if he goes to do that, he'll miss the cake making!!' I said 'no, darling, he won't. Don't worry...' I turned the page to see 'Too late, Harry!' DD3 had picked up the story line just like that. DD2 would never do that.
Sorry, I'm warbling on.