No, the minor cannot be in violation either being on the property of residence or the sidewalk in front of that property.
Montgomery County Curfew Law:
Section 1-2 (Offenses):
(a) A minor commits an offense if he remains in any public place or on the premises of any establishment within the unincorporated areas of the county during curfew hours.
Section 1-3 (Defenses):
(a) It is a defense to prosecution under Section 1-2 that the minor was:
(1) Accompanied by the minor’s parent or guardian;
(2) On an errand at the direction of the minor’s parent or guardian, without any detour or stop;
(3) In a motor vehicle involved in interstate travel;
(4) Engaged in an employment activity, or going to or returning home from an employment >activity, without any detour or stop;
(5) Involved in an emergency;
(6) On the sidewalk abutting the minor’s residence or abutting the residence of a
next-door neighbor if the neighbor did not complain to the police department about the minor’s presence;
(7) Attending an official school, religious, or other recreational activity supervised by adults and sponsored by Montgomery County, a civic organization, or another similar entity that takes responsibility for the minor, or going to or returning home from, without any detour or stop, an official school, religious, or other recreational activity supervised by adults and sponsored by Montgomery County, a civic organization, or another similar entity that takes responsibility for the minor;
(8) Exercising First Amendment rights protected by the United States Constitution, such >as the free exercise of religion, freedom of speech, and the right of assembly; and
(9) Married, had been married, or had disabilities of minority removed in accordance with Chapter 31 of the Texas Family Code.
(b) It is a defense to prosecution under Section 1-2 (c) that the owner, operator, or employee of an establishment promptly notified the Montgomery County Sheriff’s Department, or the appropriate Constable’s office, that a minor was present on the premises of the establishment during curfew hours and refused to leave.
Your property is not public, so you cannot be in offense of this ordinance being on your private property. You also cannot be in violation being on your sidewalk (or a neighbors sidewalk if that neighbor has not called police on the offender).