Lisha, I am in the exact same situation as you, except that i have 2 kids. My boy has been taken care of by my filipina maid ever since he was 3 months old and he's really really attached to her. so sometimes i feel very torn. on one hand i'm grateful that she loves him and takes care of him v well--i can banish my worries of having a maid that abuses/mistreats my child--but on the other it breaks my heart when he prefers her company or seeks her hugs when he's hurt. i got it especially bad right after i delivered, cos of my c-sect wound i couldn't carry him, or even let him sit on my lap cos he's really active and can be very rough without knowing. also, i was busy taking care of no.2 and really didn't have much time to spend with him.my maid was there for him almost 24hours (she takes care of even his night feeds). so can you imagine how broken-hearted i was when one day i asked him for a hug and he turned to my maid and hugged her like she was his mummy instead? i nearly cried...
i talked to my friends abt this. one of them said that our babies spell love as T-I-M-E. the more time you spend with them, the more they are bonded to u. for myself, i can't do anything abt the fact that i HAVE to be a full-time working mum and leave the caring of my babies to the maid. but I can decide that whenever I am home from work I spend more time with them and not let the maid take care of everything. simple things like changing diapers, feeding ...bringing him out for walks round the neighbourhood..and so far it has worked. it's not easy because i have to balance out my attention between the 2 babies. if i spend too much time with 1 the other will get too close to maid...and so the cycle continues.
after you go back to your studies, do make sure you continue to spend time with Lea. state clearly to your maid that certain blocks of the day will belong to just YOU AND BABY. e.g. the bedtime routine--evening walk, feed, bath, bedtime story/chat, and sleep. You will find that you will have very little time left for yourself but that's motherhood for you there
All i can say is there is no shortcut to being close to our babies. It really takes effort.
I personally dun think you should put her down. after all she thinks she's helping you (she IS helping you) and as u mentioned, you don't wanna sour the relationship.
After everything is said and done, dun worry too much--our babies will know who their mummies are. as they grow up they will know and come back to us..
sorry for the long post. but i really felt for u as i read ur post. because i go thru the exact same emotions as u. sometimes i can't take it and cry in the shower loh. hahaha. but then when my boy calls me 'mummmmeeeeee' i know he still recognises me as the one who carried him for 9 mths and gave birth to him.