Likely: She's been working at the same place for most of (if not all of those 10 years) and she's just basically keeping the home-grown system running and punching out some minor features. She probably got that Senior title simply because she'd put in enough time at the company. Maybe they're on .NET 4. Maybe.

If I see a technical candidate resume that has a long stretch (5+ years) at the same company and that company isn't primarily a technical one, huge red flags go up because the previously mentioned 'Senior' candidate is who generally come out of these situations. IF I get past their resume they're going to spend a lot more time telling me how they stay up to date with the world than a candidate otherwise would.