Family Planning
Joshua had the TARDIS coral and had tried numerous times to get it to grow. No matter what he tried, she stubbornly refused to. He wasn't sure if it was the Universe or him, but it seemed this little coral refused to grow for him. At first, he was severely depressed and even drew away from Rose for a while. She finally was able to draw him from his depression, but they never were able to get the coral to grow. He'd finally given it to Rose to keep safe. The little girl was alive. They both could feel her but he didn't want any more reminders of how inept he was as a Time Lord. Rose had taken the coral and hidden it away from him. She spoke to it often, when he wasn't around, encouraging her. Nothing seemed to work. Eventually, she also gave up that dream. Another took it's place, though.
They spent six years together before it happened. Nothing traumatic, exactly. But suddenly, once Rose had turned 30, she decided that she and Joshua should try for a child. They had been taking precautions, keeping her on birth control. Joshua had started taking an experimental birth control for men. Between the two precautions, they hadn't gotten pregnant. But on her birthday, in the year 2017, she finally decided she wanted to try.
The urges had come gradually. She'd stare wistfully at couples with newborns. She watched Tony grow and wondered what it would be like to have a child of her own. It seemed almost every encounter she faced now was with families. As the Ambassador of Torchwood, she dealt with plenty of different aliens and while not all of them had families, it seemed that the ones that did stuck with her more.
It had been years since any sort of invasion had happened and for once, she felt safe and content. There wasn't a looming disaster for her to deal with. That factored into her decision. Safety for her family would always be her main concern and it seemed that for once, the Universe was smiling at her.
When she told Joshua, he'd been ecstatic. He'd never really thought that she would want this. He remembered that she had once called them "little terrors". But seeing her with Tony and he understood. Not having any children of her own, she had helped raise Tony along with their parents. Joshua supposed that had given her a new perspective.
They had the financial means to raise a family, but not really the space. The first thing they did was buy a house. For nostalgia, they painted the front door blue, like the TARDIS. The rest of the exterior was painted a paler blue.
They sat down with an OB/GYN next. She explained that even if they discontinued the birth controls, it might still take a while for their bodies to readjust. Meaning, it might be a while before they even became pregnant. Both were in perfect health, as far as she could tell. She urged them to not get disappointed if it didn't happen immediately. They both nodded their understanding.
They started immediately on trying to create their family. Two years passed before they ventured to think that something might be wrong.