No restrictions for tradeskills per se but she will need tradeskill AA further along. So as a F2P she is limited to 250 AA.
Even if she were to pay for a month and auto grant the AA it would not matter since the tradeskill AA are not included in the auto grant. But she could earn unlimited AA during that month and apply those AA to tradeskill ones. So plan ahead if she goes this route and have lots of collects available to finish during that month (full collection set is bunch of AA) and do a bunch of Overseer and chose the AA reward.
She can buy stuff in the baz or sell to barter, a forager would be good for a character like Ranger or Druid. Watch deity if she is going to get involved in that. I made a few accounts with...