1) Can I merge hold it up and hold it out to hold it up and out and use in a single sentence as below. Is there something wrong about it?!!
The little girl held her skirt up and out while turning on her toe.
2) In the following sentence, does 'held her hand out' stands for stretching her hand
She held her hand out to him to cross over the muddy pit.
You can combine hold it up and hold it out to hold it up and out.
@Stangdon is right, the above is not the same as the phrasal verb hold up. In the above you are using the prepositions up and out according to their standard meaning.
Hold up (to cause or make to wait) and hold out (to wait until something) are both phrasal verbs, though. Typically the subjects of these verbs will be people (and strong context usually exists when they are not) so it's usually easy to figure out the meaning.
I'm holding the box up. (I'm holding a box that is "up" in relation to me, probably trying to prevent it from falling.)
I was held up at the police station. (I was made to wait at the police station.)
I'm holding the rope out, grab it. (I'm holding a rope "out" in relation to me)
I'm holding out for a better job. (I'm waiting for a better job.)
That broken part held up the whole assembly line. (Quite likely we mean here that the broken part made the assembly line wait and no production could be done.)
