'She's a university student, and she's doing a part-time job.' = 'She's a university student. She's doing a part-time job TOO / AS WELL.' The adverbs 'too' and 'as well' are more emphatic than 'and'. They usually come in end position.

"too" is informal and has other meanings and can be confusing because there are other words with other meanings that sound exactly the same when spoken. "as well" is more formal and easier to understand in more formal conversations. "me too" is universal and instantly understood. If you told me that you have a cell phone, I would not answer "me as well". "as well" is not an idiom. "as" means the same, equal to. "well" means to the extent of, limit or measure of. "She does not sing as well as her mother". Both "as" and "well" have other meanings. Good Q!

He went to the Zoo too/as well She had a coffee/too/as well They ran away from home too/as well You can answer this question too/as well