Yes, It is vital that the court gets the correct information to solve the case otherwise the outcome could be wrong. Even if it means testifying against someone you love. If the Relative is your...
If you are a qualified expert hired to testify yes. Otherwise no. It is your civic duty to testify if summoned.
Zoe Cummings coz she is WOW n hot n mayb shelby coz shes pretty kwl aswel but mostly Zoe hehehe
Witness's testify for and against you.
Unless otherwise directed by a judge, yes.