Kundalini, literally means coiled up energy and because it is energy, it is always form of Shakthi or Ambal.
Out of thousand names Lalitha, kundalini is also one.
Godess Lalitha as kundalini, breaks three knots , Brahmagrandhi, Rudhragrandhi and Vishnugrandhi on her way throguh Sushumna to Sahasrara, for union with her Lord Kameshwara.
So Thirumoolar, is correct. He also speaks about, one of the greatest Shakthi mantra in Thirumandhiram, Panchadasi.