Charlie died in the latest episode to air in Australia in the tragic aftermath of her shooting at the hands of Jake Pirovic (Fletcher Humphrys).
Anderson, who quit the show to pursue new projects, has now insisted that there was no other way for Charlie to bow out from Summer Bay without lover Brax.
"When I read the final script for Charlie's exit, I made sure I was in the privacy of my own home," she told Home and Away's official website. "It was written really well - it was a tragic love story and I hope the fans like it."
Anderson continued: "It's a great storyline. The writers have just done a brilliant job with these two characters - the whole journey from start to finish. Some fans will be disappointed that they didn't end up together. Well, they did, but she dies!
"But [producer] Cameron Welsh even said to me, after they've invested so much getting these two together and they've gone through so much hardship, she wouldn't just leave for [another] reason. She wouldn't just leave the Bay, so I think it had to be this way."
Revealing her initial reaction to the story twist, she confessed: "I started sobbing! But that was the initial shock. You play this character for three and a half years and you really empathise with them. You have to love a part of them - it's a little extension of you. So it's just so final, the death.
"But once I had time to let it sink in, now I'm really, really happy with the ending. It's very dramatic and it's definitely going out with a bang, so to speak!"
Meanwhile, Steve Peacocke - who plays Brax - promised that his character will be affected by Charlie's death for some time to come.
"I don't know what the writers have got in store for Brax beyond the next month or two, but it just propels him into some pretty cool stuff," he explained.
"And what I know is going to happen is that Charlie's got a lot to do with what Brax does in the future, because she may well have been the love of Brax's life."
Home and Away airs weekdays at 7pm on Network Seven in Australia and weekdays at 1.15pm and 6pm on Channel 5 in the UK.
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Watch Esther Anderson and Steve Peacocke discussing Charlie's exit in the video below: