I am a 5:45er 3x a week and I let myself "sleep in" until 6 on the one weekend morning I do my long run. I should be in bed right now, but am stupidly posting on DCUM b/c I had no down time tonight.
Really it isn't that bad. I told myself it really wasn't that much earlier then I was getting up anyway and I always feel so good to have accomplished that first thing in the a.m.
If at all possible, see if there is any other mom in the neighborhood that you can run with (you never know). That is what has kept me on track and still motivated. I just finished the Cherry Blossom 10 miler and a year ago I could barely run for 10 minutes straight let alone 1 1/2 hours.

Good luck!