Unless their right on the ledge, this is a horrible idea. If the first FAir doesn't connect, they can punish you very easily between the FAir hits. If they're right up on you though, this and FAir to BAir are great options. I prefer the FAir to BAir because at lower percents it has more follow-up options and at higher percents it has more of a "Get the hell off my ***" factor (aka knockback.)
If they are far away first fair misses (usualy intentionaly) and second one hits while they come towards me. a bair also works, but (I think) you have more hurt boxes open for that. (on the head end anyways.)
Rolling up would be the wrong option here. If the Falco is fast enough, he CAN stop the rapid jabs and punish you with any smash or tilt. Tell your Falco friend not to do that though, as it's a pretty bad idea. You can beat it with ledgehop FAir > BAir or ledgehop FAir > FAir, you just have to space it so you hit with the disjointed-ness of your FAir. If you feel like helping your friend, tell him he shouldn't rapid jab and instead should wait just outside of your ledgehop FAir range and react to what you do.
DAir is a horrible idea 90% of the time. This man is correct. Actually, even using it as a fakeout is a really bad idea unless you're pretty high up already.
The can DI + Airdodge after the first FAir. best option would be U/DThrow > Multiple UAirs. Yes they can get out after the first UAir just like they can get out of the first FAir, but would you rather 7% or 20% with an easier follow-up?