What do to about this employee? and pay question, and rude woman?

i just started a new job, it will be 5 weeks this thursday, i work 2nd shift(2-10) part time (it was supposed to be 2-3 days a week,but its turning more into 3-4 days a week.) i work as an RCA Resident care istant, but i have my STNA(State Tested Nursing istant.)by law STNAs are supposed to start at $9.00/hour but i make $8.50/hour should i bring this up to my manager. my next question is about this 3rd shift aide she is ALWAYS late! some nights she is just late 10-15 minutes late, other nights she is 30-45 minutes late, and usually we all have to stay until the 2nd third shift aide shows up. but lately they have just been making one 2nd shift person wait for the second 3rd shift aide. but this person has been on vacation for the past few days so we haven't had to deal with her being late. but tonight she called at 10(when the shifts change and get report) and said she was going to be an HOUR late tonight. its her first night back in like 4 days. i just think that that is really unacceptable, i really think that its not fair to the tired overworked/underpaid 2nd shift employees. should i bring this up to my manager as well? a while back when i was just starting, the Business manager was trying to schedule my orientation, and she asked if i could come in the next day, and i said maybe, because i had to watch my cousin, and first she said "well its not your responsibility to watch your cousin, shouldn't their parents be doing that?" i was just kind of stunned at first and i said that her parents work, and that it was my resposibility for that day that she get watched and taken care of. then the next day at orientaton i asked where i could put in the dates that i would like off at. and she replied back with "well you shouldn'y really be taking any time off because there are still people who need to be taken care of." and that jsut kind of set me on edge about her. i told my mom and she said to keep a record of these incidences and if i get any more of them, take the to the HR manager. what else can i do?