looking for these books?

Question

I'm looking for these books,one is world beneath the waves where an orphan girl is thrown off a ship and gets to experience life under the ocean as the sea creatures see it.Another is "the ancient one" about a girl who goes hiking & gets stuck in native american time after walking into a huge treetrunk. Another is called cricket & the crackerbox kid about a girl & a boy fighting over a dog.The others I'm not sure of the title, one the girl goes back to her grammas time and lives her life and finds a secret painting room in her house. Another theres a few kids and they can go to different worlds that are like ours but different,in one(its a series) there's a talking set of balls that follows her & there's some creature she has to face in an abandoned train tunnel.It's a girl & her brother,he can swim w/ dolphins like hes one of them.
The last one theres a girl who always wanted to go to a rainbow mountain she can see in the distance but when she gets there she has to face a giant. thx.

Answer 1

1) Unknown

2) The Ancient One by T. A. Barron - http://www.amazon.com/exec/obidos/ASIN/0399218998/24680e-20

3) Cricket and the crackerbox kid / Alane Ferguson
1990 1st ed.
English Book : Fiction : Juvenile audience 179 p. ; 22 cm.
New York : Bradbury Press, ; ISBN: 0027345254 : 9780027345254
Pampered eleven-year-old rich kid Cricket thinks she has finally found a friend in Dominic, who lives in the low-income houses called crackerboxes, until they quarrel over ownership of a dog and their classroom becomes a courtroom to decide who is right. http://www.amazon.com/exec/obidos/ASIN/0380713411/24680e-20

4) Unknown

5) Unknown

6) I think this is "The Farthest-Away Mountain" by Lynne Reid Banks. http://www.amazon.com/exec/obidos/ASIN/0440419263/24680e-20

The others aren't ringing any bells, but I'll come back and edit if I figure any of them out.

Answer 2

TRY amazon.com or abebooks.com or alibris.com