[Ger-Poland-Volhynia] Abbreviation used in German birth record

[Arnold, Marty & Corinne]

Hi all,
In a German birth record (1863, Freiheide, Pomeria) giving info about the witnesses, there is the name, occupation, and the abbreviation i.l.
I am wondering what the i.l. means?
Also, in front of the name of a lady, are 4 letters, Jyfr or Jgfr.  Does that mean young lady? 
Thank you so much
Corinne Arnold