"People on the street have been saying to me, 'Oh, you rat -- you shouldn't have gone to the gardai'," she said.
Siobhan's character has blown the series open by deciding to report Nidge and his gang to the gardai for threatening to throw acid in her face. But she's not getting much sympathy in public.
"They're mocking Donna, they're not mocking me, so I don't take it to heart," the 22-year-old said.
"Everyone is saying that she's a rat, but I think in Donna's situation she was just trying to help out her friend.
"What would you do if you were in her situation and your friend told you that she had been raped? She just did what she thought was right."
The Clondalkin native first got the acting bug when she was 16 and joined drama group Talented Kids.
And she scored a success with her first audition -- in RTE series Prosperity where she played teen mother Stacey. "I haven't got anything as big since, so I was delighted to get back into acting with something as big as Love/Hate," said Siobhan.
Her character has taken part in some graphic scenes during this series, from sex with bad boy Fran to having her hair shaved off following her complaint to the gardai.
Siobhan has thoroughly enjoyed the part and would like to get her teeth into similar roles in the future.
"It was brilliant to do: I love doing those action scenes," she told the Herald.
"They put bald patches on my head and loose extensions for me to pull out, as well as fake tear drops
"Having these scenes where my head is shaved and I'm distraught are great parts to play; I'd like to do a few more scenes that get people talking," added the young actress.
Other memorable scenes from this series of Love/Hate -- which has now been sold to American TV -- saw Donna dressed in a bright blue Avatar costume as she enjoyed a brief fling with Nidge's right-hand man, Fran.
While the sex scenes may not have been easy for her family to watch, it is all part of the job for Siobhan.
"They're not necessarily scenes that I want to do, but it's not as if I was made to feel uncomfortable."
And working with actor Peter Coonan, who plays Fran, was one of the perks of the job for Siobhan.
"It was grand. I got on with Peter Coonan and he just made me feel really comfortable straight away."