I was skimming through the game play around Crono's death when I noticed something I hadn't before.
Schala's last words given in the non-DS versions of the game include something to the effect "I will use the last of my pendant's power to send you to safety." Afterwords, she falls to her knees, and mourns for Crono. However, there's a nifty bit of a sparkle left behind in that scene, the remnants of Crono's possessions, presumably the pendant, left alongside Schala.
Well, if she's left with a near un-powered necklace, what if/why wouldn't she then just take the powered necklace and use it's powers to travel to safety. Heck, with juice to spare, she could then send off the non-glowing necklace after Marle and company. (as seen to be not-sparkly in the remains of the Earthbound village post tidal wave)