I will graduate this May from my degree program and was recently offered a full-time role that would start in end of June. However, about a month ago I accepted a Spring & Summer 2021 research position a month ago which supposedly would last till August. Though I assumed the position to be unpaid, the professor with whom I work told me earlier that she would be able to offer a small compensation over the summer and the exact amount would depend on the number of hours and weeks I can commit to.
I am not sure what would be the appropriate way to inform her that I have obtained and accepted a full-time offer that would start earlier than she would like to. I appreciate your help in this matter!