my kitten is only 14 oz at 3 to 4 weeks should i be worried?

PLEASE HELP ME! IM DESPERATE!!! i recently took in a kitten who was abandoned by her mother....with much research i was able to determine her age, but i am very worried about her weight...she is VERY skinny for her age, and weak...what can i do for at home? i am not able to afford the cost to take her to the vet and i feel terrible about it....i just want to know if there is anything i can do for her....your inputs would be greatly appreciated! thank you! 

The last litter of kittens I fostered were an average of 416g - 14 2/3 oz - at 21 days.  I don't have a weight for 28 days as they no longer fitted on the scales!

They were good healthy kittens and if yours is 3 weeks old then it's a good size.  However a kitten should not be skinny and weak.  How did you decide how old it is?  And what are you feeding it, and how often?

It does need worming.  You can buy Panacur online in the UK without a prescription and that is suitable for your kitten - the weaker of the two suspensions will be easiest to give her an accurate dose.  You will need a small syringe as well, a 10ml one.

And I know you have the best of intentions, but you will have endless problems if you cannot afford a vet.  Love is great but it doesn't vaccinate, neuter, deflea or worm.  If you are in the US look at the stuff about low-cost vet care, if in the UK consider handing her to the Cats Protection.

I found out how old she was by her teeth, i asked my aunt who is a vet...but she lives in south America. I have been giving her PetAg replacement milk every 2 to 3 hours. and her sleeps a lot...she does become curious and wonders around but then becomes tried and goes back to sleep...and i have been feeding her with a syringe....that seems to be working soo much better then the bottle, and she just recently learned how to use the litter and has been doing great! i just wanted to make sure i am doing the right things for her...and i cant afford to pay for vet visits right now but i will definitely save as much as i can because i dont want anything to happen to her....thank you so much! i feel sooo much better now!! 

If you are right about her age she is old enough (just) to start introducing solid food.  Put a little out in a shallow dish, maybe smear a little on her paws and/or face and see if she gets the taste for it.

These might be useful:

http://www.fabcats.org/behaviour/understanding/kitten.html

http://www.fabcats.org/owners/kittens/handrearing.html

The 2nd one mentions weaning some distance down the page.

Your kitten will need vaccinating in 2 months, and neutering not that long after.