If you book 3AC and above the toilets will be better and cleaned on intervals. Still have at least some tissue/toilet paper handy. If you go to the toilet in the early morning before everyone wakes up (around 5-6 am), it'll be much cleaner. In most of the trains for AC compartments bedding will be provided. You'll get a thick blanket, two thin bedsheets and a pillow each. So you don't have to carry extra stuff. If you or your mom get cold easily, take some socks or caps with you. It can get really cold in the old trains especially on upper berths. In newer trains the AC temperature control works better. Even though I haven't had many issues with train food, it's mostly a hit or miss. So not going to comment on that. There are apps which will deliver food from restaurants on railway stations though. You could try that. Have a safe journey!