"Lightning," she replies after a few seconds of surveying the landscape and directing her horse into the direction of the city. But Lightning hesitates before holding her hand out to Saber, so she can help her onto Odin behind her. "I'll give you a lift. There's room for one more."

It's only fair that she helps the woman out, even if she didn't ask for help earlier. And to give her a ride when Saber's the one on foot-- no telling how far off the city is, and they can make better time when Odin is galloping at full speed.