The more popular account of Lakshmi Devi's manifestation is the episode of the churning of the ocean. It is mentioned in the MahAbhArata as well as in the PurAnas.
According to MahAbhArata, Lakshmi Devi Or Sri appeared from clarified butter (or Ghee) during Samudra Manthana as sitting on a white lotus:
SrirantarmutpannA ghritAt pAnduravAsini ( Adi Parva 18-35 )
PurAnas like the BhAgavata (8.8.14) and the Padma (Srishti Khanda 4-58-59) also repeats the same event.
But Lakshmi Devi's parents are also mentioned in not one but many PurAnas as Maharshi Bhrigu (father) and KhyAti (mother).
Bhriguh KhyAtAm MahAbhAgah PatnyAm PutrAnajijanat |
vidhAtAram sriyancha bhagavatparAm ||
From MahabhAg Bhrigu's wife KhyAti's womb were born three children
named DhAta, VidhAtA and Bhagavataparayana Sri (or Lakshmi).
BhAgavata purANa 4.2.42
The VishNu purANa says the same:
Devau DhAtA VidhatArau Bhrigoh KhyAti Rasuyataah |
Devadevasya Patni NArAyanasya YA ||
Bhrigu's wife KhyAti gave birth to two Devas called DhAtA and VidhAtA
and Sri who is the consort of NArAyana.
VishNu PurANa's first part, 8.13
The BrahmAnda purANa also repeats the same:
Bhrigoh khyAtirvijajnehatha iswarau sukhadukkhayoh |
SubhAsubhapradAtarau sarva prAna VrtAviha ||
Devau dhAtA vidhAtArau
manvantara vichArinau |
TayorjyeshthA tu bhagini devi srir loka
sA tu nArAyanam devam pati mAsAdya shobhanam |
NArAyanatmajau sAddvi valotsAhou vyajAyat ||
Bhrigu and his wife KhyAti gave birth to two sons named DhAtA and VidhAtA and a daughter named Shri or Lakshmi. Lakshmi obtained as her husband NArAyana and thereafter gave birth to two sons called Bala (strength) and UtsAha (enthusiasm).
BrahmAnda purANa 29. 1-3.
And, that is why MahAlakshmi is also known as BhArgavi.