I can't tell you if it is too little or too much water. But I can say that you should let them dry out between waterings, and water enough to get the soil damp. They will start to droop a little if they need water, so you should be able to tell easily whether it is too little water. I always end up watering as soon as I see the drooping, but always feel guilty that I waited that long. I just looked at mine, and it has brown tips on some of the leaves. Dried out brown tips. So I can guess that it is from too little watering from my experience.

But I wouldn't worry too much. I have had this plant for 30 years or more and it is still alive and kicking and it still blooms. Some leaves die out and new leaves grow. You can't kill this plant unless you never even look at it so don't see when it needs water.

and have been told you can't kill them. I have, every one I ever got I managed to kill. Tried very hard to treat them right but did something wrong.

watering. Then I give it a good drenching and let it sit with the bottom of the pot in the water (I use one of those clear plastic saucers they sell at the hardware store-- about 5" across and 1" high) for about an hour. Remove it from the water let the excess water drain away and wait until the next wilting.

Have you had this plant for more than a year?

If so, it could e a buildup of mineral salts in the soil. Time to re-pot with fresh potting soil.

Otherwise there has been very good advice on how to water.

The browning isn't a big deal. I bring mine outside for the summer (shade) and the get very happy! When I bring them back in before frost, I mist them with water (it's much dryer inside) and that does the trick, along with regular watering, hopefully before they get to the wilt stage. I give them a fairly diluted fertilizer now and then. All 3 pots are blooming right now and also bloom outside- very pretty. I love them!