Bottle for last feed before bed

Sept07b2b

So my LO is 15 weeks old and is EBF.  I have found recently that she gets very frustrated with her last feeding before bedtime (~8 or 8:30).  I understand my supply is at its lowest in the evenings, but I also think it's because she is tired, so she doesn't want to expend the energy to nurse (she's never been one to fall asleep while nursing). 

I returned to work a couple weeks ago, and she's been getting some bottles from the nanny, although she doesn't seem to love the bottle and only consumes about 8 oz while I'm at work and doesn't seem to have any trouble nursing when I get home from work or on the weekends, so I really think she's just tired.  Last night when I knew she was hungry, but she kept pulling off and crying (presumably because she was really tired and not getting a ton of milk), I decided to give her a bottle of expressed milk (3 oz) and she slept through the night (10 hours) for the first time!!! 

So my question is, do you think the bottle has something to do with this or was this a fluke?  Is this a bad practice to start?  Will this make her a lazy nurser in general?  I will pump before going to bed to make-up for the feeding, although I honestly HATE pumping and would really like to avoid pumping at night if at all possible, but if it means my LO STTN, then it's worth it.  Has anyone else done this?  If I don't do a bottle, any suggestions for getting a very tired, but hungry baby to nurse?  TIA!