I think Liliana is just beautiful, with a special meaning to it, and timeless. Ellie is VERY trendy today, and will be dated in the future - You chose timeless names for your other children, I think Ellie would be going against that (meaning - in 15 years, just about every Ellie will be in high school). Not that it's not a beautiful name, but it's a trendy and I tend to stay away from trends. Liliana on the other hand is easy to pronounce, not madeup but still original, and will age well.
I REALLY don't like the K in Kaleb, mainly because it looks madeup. It will also constantly be misspelled, and look dated in a few years when the 'K' trend passes as well... Caleb is beautiful, timeless, and will age wonderfully and look good on a grown man. I have a hard time imagining a grown man sitting behind a desk with 'KALEB' on his nameplate - just seems less mature to me. JMHO.
Again, I prefer the original and timeless spelling of Isaac (as opposed to Isaak) but it's not as obvious when the K is at the end of the name. Between Caleb and Issak I much prefer Caleb - but between Kaleb and Issak I much prefer Isaak because I can't get past the K at the beginning =)
Good luck in choosing, I'm sure you'll find the best fit for your family in the end! Hope the rest of your pregnancy is quick and less painful.