a little discouraged

so I have been babysitting now for a little over a month and I think I do a pretty good job and i'm pretty sure the kid likes me but a few days ago the mom asked me if me and lexi were getting along. I thought maybe it was because one day she was pretty moody and tired but wouldn't sleep(her mom said she had a soar throat that night). her mom said something about lexi saying she didn't want me to watch her which I thought was pretty upsetting cause I thought we were getting along. then today when the mom left for work she asked me if I though if lexi was doing Ok... the mom said it seemed like lexi has been acting weird. I don't know what i'm doing or if i'm doing anything but I just feel like the mom thinks that lexi is miserable with me or something. it didn't make it any better that when the mom got home from work the other day lexi woke up from her nap crying. she has never woken up crying. and she rarely cries while I watch her. she hadn't been eating i'm pretty sure she has been sick for the past week or so but the mom didn't have any special instructions or medicine for the girl.. she has been sneezing but I wouldn't give the kid medicine without the mom telling me to. the girl seems back to normal today. she ate breakfast and lunch and she has been talking more and isn't as easily upset. i'm sure the girl was just sick but it is frustrating that the mom doesn't realize that. I am going to try and leave more of an update for the mom each day... it is hard though cause I don't seem her half the time that i'm done babysitting... either the older sister or the dad take over when i have to go to work. I know I am always full of self doubt when it comes to things like this cause I do%mt want people to think i'm doing a bad job.