When Una first appeared in Carrigstown, she quickly became attracted to mechanic Keith McGrath. The two soon started a relationship in early 2007. Niamh Cassidy became jealous and Keith became more attracted to her than Una. Keith was going to break up with Una but didn't when they found out she was pregnant. However tragedy stuck when she experienced a miscarriage. Keith soon dumped Una to begin a relationship with Niamh, leaving a devastated Una with nobody.
Soon after Una was seen frequently around Carrigstown and it was obvious her feelings for Keith never went away. In March 2008, Una had started dating her boss Ollie and was doing well at her job in the Haven. Keith, however, was becoming bored with Niamh. One day he calls around to her apartement. Una lets him stay for dinner but when he starts talking about how good they were together she asks him to leave. Keith then kisses her and ends up spending the night with her.
Due to Niamh's sister's friend who also works at the Haven seeing Keith leaving Una's the next day, everyone found out about the affair. Una then slapped Keith for thinking he was gloating about it and Ollie consequently dumped her but allowed her to stay on at The Haven.
In July 2008, Keith proposed to Una and she accepted.