Some people may not like the way the story ended, but I couldn't end it any other way, so I hope some people liked it for what it was too.
I read my first Harry Potter fanfic about a week before I started on this story. While I love both Harry and Snape equally, I was more interested in reading Snape fic for a few reasons:
I'm not a shipper when it comes to Harry Potter so I have no real interest in reading Harry/Hermione/Ron/Ginny/Draco/Snape fics, and whatever other pairings are out there.
I feel I know Harry pretty well as he's the main character in every book and we see almost everything through his eyes.
Snape is a very ambiguous character on the other hand, so I was interested to see what other people made of him. I read a few interesting stories, and I noticed that along with all the various shipper fics associated with Snape, there were also a significant proportion of "Snape discovers he has a long-lost child" fics. I found this pretty interesting, and thinking about it I thought – yeah, Snape is totally the kind of guy you could imagine this happening to! He's quite reserved and a bit spooky, not to mention the Death Eater associations – I could see him involved with someone who backed off (or ran away) because he was a hard person to be around, or because of all the Death Eater stuff.
I read of a few of these types of fics, all the ones I came across basically (bearing in mind that I have barely tapped the surface of Harry Potter fanfiction, it isn't a lot). In every completed one I read Snape and the kid always end up bonding and loving each other and it ends on a happy note. This was interesting enough, but immediately a scene came to mind of Snape standing outside Hogwarts, watching his child leave him because he was too hard to be around. I wanted to read something like that, but couldn't find anything, so I decided to write this story – all based on that one scene. I find Snape to be a somewhat tragic character, so I think happy endings don't necessarily suit him – not until we know his fate from book 7. I wanted my story to be a semi-plausible back story to Snape so I couldn't give him a happy ending anyway as it would have detracted from my idea of Snape in the books.
I hope I kept Snape in character as much as possible. He fits in quite well with my idea of what Snape is like, but everybody will take away a different interpretation so I just hope I did him justice.
A few more random points:
Every Snape's kid fic I've read so far had the kid being in Slytherin. I think it's funnier if his kid is in the house he hates so that's why Ellie ended up in Gryffindor.
I wanted Ellie and Snape to clash a lot so that it would be believable that she would walk away in the end. I had a lot of fun writing their battles and I hope they came across as in character. I love how they would start out having normal conversations but then end up yelling at each other!
When I was writing this, I felt that at all times Snape did love Ellie – even in the beginning when he first sees her as she is about to be sorted there's just something there that sets her apart from the other students. When he suspects that she's Claudia's daughter, even though he doesn't realise that he's her father at the time, I think there is this unwanted affection for her just because she's Claudia's daughter, even though he kinda hates her for that too. I think that's part of what initially ruffles his feathers about her – he feels a connection to her because of her mother and he absolutely detests that. I actually found myself thinking about Snape and Harry when I was writing this and now all those Snape/Lily theories I've heard about are starting to make a lot more sense. Hmm…
Anyway, I think it's very "Snape" for him to love someone but to not be able to actually express that love to the person. With Claudia he was younger and he was a little bit more open with his affections, plus he was actually in romantic love for the first time so he was less weary. With Ellie she's a child who has been sprung on him, she irritates him, and he's closed himself off from "love" for so long that he just can't open up the way he might have been able to had he and Claudia remained together. He also feels this burden over the Death Eater/Order of the Phoenix stuff so he feels he needs to keep away from personal attachments for those reasons. It's sad for him and Ellie because without that hanging over his head they might have been able to forge some kind of relationship.
About what happens next:
I don't know if Ellie and Snape ever see each other again. Depending on your personal preference – if Snape is really a bad guy then no, they don't; if Snape is really a good guy and he doesn't die then yes, they do. I'm hoping Snape is a good guy. ;-)