Indeed, she [Mary] even presented an offering to the Jewish priest arising out of her sinful condition (Luke 2:22-24) which was required by law (Lev. 12). This would not have been necessary if she were sinless. (p. 310)
Matthew 3:6, 11, 13-15 (RSV) and they were baptized by him in the river Jordan, confessing their sins. . . .  “I baptize you with water for repentance, . . .”  Then Jesus came from Galilee to the Jordan to John, to be baptized by him.  John would have prevented him, saying, “I need to be baptized by you, and do you come to me?”  But Jesus answered him, “Let it be so now; for thus it is fitting for us to fulfil all righteousness.” Then he consented.*Mark 1:4-5, 9 John the baptizer appeared in the wilderness, preaching a baptism of repentance for the forgiveness of sins.  And there went out to him all the country of Judea, and all the people of Jerusalem; and they were baptized by him in the river Jordan, confessing their sins. . . .  In those days Jesus came from Nazareth of Galilee and was baptized by John in the Jordan.*Luke 3:3, 21 and he went into all the region about the Jordan, preaching a baptism of repentance for the forgiveness of sins. . . .  . . . Jesus also had been baptized . . .
Likewise, Jesus observed the Jewish feasts (Jn 5:1; 7:14, 37): most of which involved animal sacrifices that atoned for sin (Lev 5:9, 12; 9:7; 16:25; 2 Chr 29:24, etc.), and casually referred to the presentation of gifts to the altar, in teaching His followers (Mt 5:23-24). Thus, He participated in rituals that presupposed sinfulness on the part of those who participated, brining an animal or grain-offering to atone for their sins. Yet He was without sin.
Last of all, He observed the Passover (Jn 2:13; 12:1), and indeed the Last Supper was a Passover ceremony (Mt 26:17, 19; Lk 22:8; Jn 13:1): which involved animal sacrifice. Jesus’ own death continued this theme, which had been an instance of “types and shadows”: as He was the “Lamb of God” (Jn 1:29, 36; Is 53:7; Rev 5:6, 8, 12-13; 7:9-10, 14, 17; many other instances in Revelation). He was to be the sacrifice for our sins (Heb 9:12), rather than animals (Heb 10:4). Yet He had observed Passover, even though without sin.
Therefore, by analogy, Mary’s participation in Jewish rituals does not at all prove that she sinned, since we know that Jesus was sinless, and participated in all of them.
Thus, Geisler’s argument here utterly fails.