Never ask loved ones or blood relatives to critique your manuscript. They can read it, but only with the understanding that their job is to cheer you on. Their only responses shall be "That’s great, honey!" or "Wow! Now I know why you’re so excited!" or "I am so proud of you!"
If they say "You spent all that time locked in the closet and this is what you produced?" you are allowed to burst into tears. (I do not encourage full-blown temper tantrums complete with banging head against floor, but I understand that sometimes they are necessary.)
You need peers – people who are also writing and who read a lot – to give you a decent critique of your work.
Rule of thumb: don’t ask loved ones to read your manuscript and don’t ask critique buddies to pick up their socks.
EDITED TO ADD: Several of you commented that if your loved one is a writer, s/he can offer extremely helpful critiques. I agree. That works in my family, too. But I think it is rare. My tips this month are written with new NaNoWriMo participants in mind and I am guessing that few of them have a loving, in-house, qualified critiquer.