About Yvonne
Yvonne Costelloe’s academic background includes studies at Mercyhurst College and the University of Dayton. She pursued undergraduate and graduate coursework across those institutions, forming the foundation for a legal career that combines courtroom familiarity with client-facing responsibilities. Her time in the classroom influenced how she approaches problems: methodically, and with an eye for detail.
After completing her studies, Costelloe moved into legal practice. Over the years she has worked on a range of matters that required both negotiation and litigation skills. Her work has involved drafting pleadings, preparing discovery, and guiding clients through procedural steps in state and federal proceedings. She has experience conducting factual investigations and preparing witnesses for testimony.
Colleagues describe her as steady in the courtroom and practical at the conference table. She has handled settlement discussions and trial preparation. Cases she has worked on have demanded careful legal research and an ability to translate complex rules into clear advice for clients. She approaches each file in the way many seasoned practitioners do: by identifying the key issues early and organizing workstreams to address them efficiently.
Her practice has required familiarity with motion practice, evidentiary matters, and case management protocols. She has interacted regularly with opposing counsel, court staff, and expert witnesses. That experience has given her a working knowledge of litigation mechanics, from initial pleadings through dispositive motions and trial readiness.
Costelloe joined Jan Dils Lawyers at Law, where her role centers on representing clients and managing cases from intake through resolution. At the firm she takes on responsibilities that include client interviews, drafting legal documents, and coordinating with colleagues on strategy. Her day-to-day work balances courtroom preparation with client communication and administrative oversight.
Outside the office she has remained engaged with legal developments, following changes in procedure and precedent that affect her clients. She stays attentive to shifts in local practice and court rules so she can adapt case plans when necessary. Her current practice focuses on client representation in contested matters, case preparation, and negotiating resolutions on behalf of individuals and entities.
