This paper investigates International Research Collaboration (IRC) among European Union (EU) countries from 2011 to 2022, with emphasis on gender-based authorship patterns. Drawing from the Web of Science Social Science Citation Index (WoS-SSCI) database, a large dataset of IRC articles was constructed, annotated with categories of authorship based on gender, author affiliation, and COVID-19 subject as topic. Using network science, the study maps collaboration structures and reveals gendered differences in co-authorship networks. Results highlight a substantial rise in IRC over the decade, particularly with the USA and China as key non-EU partners. Articles with at least one female author were consistently less frequent than those with at least one male author. Notably, female-exclusive collaborations showed distinctive network topologies, with more centralized (star-like) patterns and shorter tree diameters. The COVID-19 pandemic further reshaped collaboration dynamics, temporarily reducing the gender gap in IRC but also revealing vulnerabilities in female-dominated research networks. These findings underscore both progress and persistent disparities in the gender dynamics of EU participation in IRC.