PROB §8251: (a) The petitioner and any other interested person may jointly or separately answer the objection or demur to the objection within the time prescribed in the summons.

(a) The petitioner and any other interested person may jointly or separately answer the objection or demur to the objection within the time prescribed in the summons. (b) Demurrer may be made on any of the grounds of demurrer available in a civil action. If the demurrer is sustained, the court may allow the contestant a reasonable time, not exceeding 15 days, within which to amend the objection. If the demurrer is overruled, the petitioner and other interested persons may, within 15 days thereafter, answer the objection. (c) If a person fails timely to respond to the summons: (1) The case is at issue notwithstanding the failure and the case may proceed on the petition and other documents filed by the time of the hearing, and no further pleadings by other persons are necessary. (2) The person may not participate further in the contest, but the person’s interest in the estate is not otherwise affected. Nothing in this paragraph precludes further participation by the petitioner. (3) The person is bound by the decision in the proceeding.