She's 37 years old in Series 1 and 43 years old in Series 2, 170 cm (5ft 7in) tall, and her weight is secret. (She probably will be 45kg or so).
As Chris's busy mother, she is rarely ever seen around her house. She is a very caring and kind mother who only wants what's best for her son. She has been regretful of how her busy lifestyle constantly keeps her away from her son. Whenever they get together it usually isn't for very long and it has led her to believe that she is indeed a terrible mother on occasion.
In reality, Chris has been affected by her and her husband's absence more than even he was aware of. His refusal to see his friend Sonic the Hedgehog leave and go back home to his own world was mostly due to the thought that he'd be losing another stem in his relationship with the people he liked. Linsey and Nelson were just as oblivious to this as Chris was but they made it better in the end when they remembered a special vacationing area they all used to visit when they seemed more like a normal family.
She is also very over-excitable and often takes things to the extreme. For example, she sky-dives from a helicopter in order to land on the balcony of her house just so she could visit Chris when he had small cold. She sometimes tends to act a bit oblivious to certain things as well. She's a terrible cook as shown in the episode when she was first shown visiting Chris. Her pancakes were so incredibly charred that they broke apart when lifted. Everything else on the breakfast table was virtually unidentifiable.
In Sonic XEdit
Her role in the Sonic X anime was a minimal but recognizable one. Due to her constant absence, Chris had developed unnoticeable problems dealing with separation and relationships. It wasn't resolved until the second to the last episode of season 2.
She is a movie star and is highly famous. She has made numerous appearances throughout the show despite being away on business. Her first appearance had her as the guest of honor at a party Chris held for her coming home. She had to leave before she was able to see it through however.
Other notable appearances include an episode where she had found a yellow Chaos Emerald and gave it to Cream the Rabbit simply because the color seemed to match. There was a time when Nelson Thorndyke, her husband, bought the purple Chaos Emerald from a jewelry shop and constructed a complicated plan to give it to her during one of her movie screenings for their anniversary. However, it was stolen by Dr. Eggman in the end.
Story of Joining Sora's TeamEdit
When her son Chris was recruited on the team, Chris asked for his family and friends on the Gummi Ship after he turned back to an adult. When Linsey and the others came on the ship she was happy to see her son again but when she saw some of the members that are monsters she decided to stay to keep her son safe, and doesn't approve of Chris going on missions.