Create TabSheet and Frame based on item checked in a TreeView

I have a TTreeView on my form which gets populated from a DB table. The list currently has 22 items and all of them have checkboxes that can be checked.

The TTreeView is on a TForm that has a TPageControl with a pre-made TTabSheet and all other TTabSheets are created dynamically and assigned TFrames to them.

My current code to create a new TTabSheet at runtime looks like this:

procedure TForm1.Button2Click(Sender: TObject);
var
  aTab: TTabSheet;
begin
  aTab := TTabSheet.create(self);
  aTab.Name := 'tabProduct_' + IntToStr(PageControl1.PageCount+1);
  aTab.PageControl := PageControl1;
  aTab.Caption := 'Product ' + IntToStr(aTab.PageIndex);
  LoadFrame(aTab.PageIndex);
end;

The code for the LoadFrame() procedure is:

procedure TForm1.LoadFrame(const index: integer);
var
  aClassName: string;
  aFrameClass : TFrameClass;
  I: Integer;
begin
  if index >= 50 then
    raise Exception.create('Max product count reached');
  if index >= Length(frames) then
    SetLength(frames, index+1);

  if assigned(frames[curIndex]) then frames[curIndex].hide;

  if not assigned(frames[index]) then
  begin
    if index = 0 then
      aClassname := 'TframeClient' // client
    else
      aClassname := 'TframeProdus'; // anything over pageindex 0 is a product
    aFrameClass := TFrameClass(GetClass(aClassname));
    if not assigned(aFrameClass) then
      raise exception.createfmt('Could not find class %s', [aClassname]);
    frames[index] := aFrameClass.Create(self);
    frames[index].name := 'myframe' + IntToStr(index); // unique name
    frames[index].parent := PageControl1.pages[index];
    frames[index].align := alClient;
  end;
  frames[index].show;
  curIndex := Index;
end;

Other relevant code:

type
  TFrameArray = array of TFrame;

<...>

  private
    { Private declarations }
    curIndex: integer;
    frames: TFrameArray;
    procedure LoadFrame(const index: integer);
  public
    { Public declarations }
  end;

  TFrameClass = class of TFrame;

<...>

Let's say I check the box next to items 1, 5 and 13 in the TTreeView.

How can I determine that and modify the Button2 code to create TTabSheets and their TFrames only for the items I have checked in the TTreeView?

Meanwhile, managed to figure out this approach and it seems to work well

procedure TForm1.Button2Click(Sender: TObject);
var
  aTab: TTabSheet;
  i: Integer;
begin
   for i:=1 to TreeView1.Items.Count do
begin
   if TreeView1.Items[i-1].Checked then
    begin
      aTab := TTabSheet.create(self);
      aTab.Name := 'tabProduct_' + IntToStr(PageControl1.PageCount+1);
      aTab.PageControl := PageControl1;
      aTab.Caption := TreeView1.Items.Item[i-1].Text;
      LoadFrame(aTab.PageIndex);
    end;
  end;
end;