My daughter registered her iPhone with my Apple ID. How can she make her own Apple ID and keep all her information (pictures and contacts and Apps)?

Click here to see how to 'Create an Apple ID' = create an Apple Account. --> https://support.apple.com/HT204316

For a child: Create an Apple ID for your child - https://support.apple.com/HT201084

Merging Apple Accounts or transferring data is not officially supported, nor can it be done easily or completely.

Apr. 2018 post by ASC helper Winston Churchill on transferring data from one Apple ID to another. https://discussions.apple.com/message/33333380#message33333380

Feb. 2021 tips from Eric Root https://discussions.apple.com/thread/252468781?answerId=254653802022#254653802022

Look into using Family Sharing to continue to be able to use items purchased with one Apple ID with other Apple IDs.

Family Sharing - https://support.apple.com/HT201060

Set up Family Sharing - https://support.apple.com/HT201088

Fortunately when you sign out of one ID it asks you in most cases if you wish to retain the data from it on your device. Say yes and then delete individual items you do not want.