Don't mind them...as far as I can tell, they've been acting weird since I got moderized...>_>
It's the magus icon. If just feels so... wrong not to see the Lavos icon next to your name.
Also, like I say...I'm not familiar...GLP?
Guardia Line Paradox; Marle, Doan, and the entire Guardia Royal Family (possibly including Schala and Magus, but that is uncertain) should cease to exist as soon as Ayla leaves the past, as she is then no longer in the past to have the children that will eventually lead to the Guardia Royal Line.
My explanation to such a paradox is ... really besides the point, but if anyone cares, read this paragraph. If not, skip to the next. Anywho, my explanation to such a paradox is what I like to refer to as "Time Index." Like the index of a book, each individual person has a personal timeline along which certain events happen. Those events only happen at the proper page number (or point in time). For a normal individual, a change at any point in the timeline will immediately effect the rest of their timeline, from a Time Error perspective. However, for a time traveler, events can only change when both the individual's age and the events proper place in that person's time line match. That is, when Ayla becomes a time traveler, she can't suddenly not have children when she was (lets say) 30 if she isn't 30 yet. Only events in a time traveler's past or present can change the timeline; not events in a time traveler's future (which is why Crono doesn't defeat Lavos before he actually faces him in the final battle).
Anywho, the problem with Leah is that she makes no sense. Was she sent from the 65,000,000 BC to 1020 AD? If so, how? Gaia's Naval is clearly supposed to be a "Lost World" sort of setting, but does this just imply the continued existance of old life forms or does it imply time travel? Given how poorly about 1/3 to 1/2 of the characters in CC were designed, I'd say that the designers intent was simple along the lines of the following:
Designer #1: "Gee, people liked that cave-girl from the first game. We should include another one."
Designer #2: "Ayla didn't live in a cave, she wasn't a cave-girl. But that would be fun. What sort of character development should we plan for her?"
Designer #1: "Oh that is easy; she needs to say '-um' after a lot of words. Like 'its clobberin' time-um'."
Designer #2: "That's a bad accent, not character development."
Designer #1: "I'm sorry, I spaced out there for a moment. Did you just agree with using '-um' for character development? Sorry, don't have time for you to repeat your answer, I'll assume it was a yes. Now... what about including some guy with no pants?"
In short, I highly doubt the designers even considered the implications of Leah or the subsequent implications of her being Ayla's mother. Doesn't mean that we can't consider the implications for them, but unfortunately designer oversight does make for some very nasty plot holes.
It is quite possible that Gaia's Naval and the Mystic Mts. do have a temporal connection. However, without the gate key, how would Leah get back in time anyone (or forward in time in the first place)?
To note... Leah (and the Green Dragon) are only present in Home World. The Ghost Children, which are only present in Home World, specifically state that they no longer exist in that time line (or something to that effect). It may be that since Leah is present in 1020, she actually is removing an important element of the guardia royal line from history. We only assume that in Home World Marle existed.