Lillylemon

Hi, I'm a late 20s female, vegetarian for 20+ yrs but only vegan for around 5yrs or so. I am really slim, 5ft 5ish, 8 stone 3lb roughly. I feel too skinny though. I gave birth 19 months ago & still breastfeed a couple of times a day so the weight fell off me. I have always found it hard to gain weibght. I would like to gain shape & muscle definition but haven't a clue where to start. I am a stay-at-home Mum but have plenty of help with childcare so can train in the day & or evenings. We have a gym at home in the garage, with free weights, machines, cross-trainer & running machine. I need some sort of orogramme/routine to follow. Any ideas?