8 year old daughter talking to me like shit out of nowhere..

My eldest child is 8 years old, i dont know if its the age or a taste of whats to come in the next few years but the past few weeks she has started talking to me like i am shit and i wonder am i not being strict enough with her? am i going wrong somewhere? is this a normal phase? For example.. she says when i asked her to clean her room that i do nothing all day and maybe i should start doing more around the house. Ive done a 3 hour antenatal visit at the hospital today with a 2 year old, hung 3 loads of washing out, made kids breakfasts and walked them to school in the stinking rotten heat, made lunches, cooked and cleaned and the loungeroom is a mess. I just need to sit down im so tired. If i ask her to pass me the nappy wipes or something she will say that i am so lazy and dumb and why should she have to do "everything". I am sick of it. I feel like my 8yo is disrespecting me and i have no idea how to curb the behavior as previously she was an absolute angel of a kid. Nothing major has happened only she went back to school last week. I do notice a difference in her behaviour once shes been spending time with her good friend but idk