An adult wants to open an account, savings and checking for their minor child and allow them access to the funds. We have them complete a parental guarantee form but does this form need to be notarized or is it up to our discretion?

Unless your form has a (c) notice, it was probably designed by a bank employee or bank counsel; it is not a standardized form. If it includes provisions for notarized signature I suggest you always have it notarized.