Tranny slips in second

[elmobile]

Just a bit it slipped in second I made me a paper funnel with tape and a straw and added the missing quart of tranny fluid I drive this 93 festy alot and use it as a work car she uses a little oil but never a tranny slip.was fine after I added fluid... what causes this its gone 3000 mile withoout any problem driven daily does great on the freeway shakes a little but its common in Festys.What should I do If I keep having slip issues?? The car was down a quart of T/F ive had it a few months and love the little car is there something I can do outside of rebuild or replace the tranny I dont have alot of loot at this time and badly need the car to make some.... what about some Lucas Tranny seal or something... as far as I know the car is fine right now like I said I put some fluid in it and it stopped slipping wifey drove it to wally world and said the car seemed funny when she foirst took off but I did tell her to listen to it so mabey I freaked her out and she over exaggerated she said it seemed funny sputtering then it was fine on her 20 minute drive I havent drivin it will in the am for work any suggestins
Dayton Ohio