Wow daily? Actually, you don't really need to work your abs that often to see changes. In fact, it may even be counter productive. Your abdominals are muscles. When you work out you are tearing the fibers in the muscle and then they need to rest. During a day of rest they recuperate and rebuild stronger and look bulkier.
Now, with that out the way. I also want to add that it doesn't matter if you're 135lbs.. The visibility of your abs depends on the amount of bodyfat percentage. You can be slim and have a high amount of body fat. I don't remember the right number but I think women have to be down to about 10% bodyfat to start seeing abs.
I think it would be fine to do less ab work. Maybe every other day... Honestly, you can do so much less and still get amazing results. The key is that you have to make sure that you are pushing yourself further each day in regards to intensity, and that you are using proper form. Try to add some weights to your ab workouts and really feel it. Then make sure you're getting enough protein in your diet to support building new muscle, and let it rest.
As far as time goes, like I said... It depends on your bodyfat %.. You can do a million situps daily, but if your bodyfat isn't right.. It won't show! The muscle will be there, but under a layer of fat. (Not calling you fat by the way, but people naturally hold fat).
Assuming your bodyfat is fine, and you're working out correctly.. It may take about 2 months to see any significant change. May be sooner.. Who knows.. Every body is different! You change daily so I think you should just track your progress with pictures.
Goodluck!