1. I have noticed that the soil on my peace lilly has spots of yellow in them, is it a mold, and should I change the soil?

2. Also, on my mothers' peace lilly, the leaves have started to change color, they are turning brown on the ends? What can she do about this?

Thank you

Just take out the top couple inches and add new good draining sterilized soil. Give the plant better air circulation around it if is doesn't have that already Keep it away from cold drafts and water less.

The peace lily can get brown tips for a few reasons. Under or overwatering, too much fertilizer, or using hardwater which contain Chlorine, Fluoride and minerals/salts.Try using bottled of rain water if you think it's because of hardwater. Even though water sitting out can dissipate Chlorine, it won't Fluoride.

It's sounds like it's either been overwatered, overfertilized or possibly both. The top couple inches should dry between waterings. The soil below that should feel just slightly moist If you fertilize, it should be diluted down with water, never full strength and only used sparingly. If you have several plants in one pot, you might be able to save a couple as long as the roots didn't rot. If just some of the roots have rotted, cut those ones off, leaving just the healthy ones and transplant it into some very well draining soil into a small pot. You can also grow these plants in water.Give it indirect light

The tips of the leaves on my peace lilly are turning dark brown and yellow.I do not use fertilizer,so I dont think thats the problem.What is wrong??